CN112361537A

CN112361537A - Multi-split air conditioning system and oil return control method and device thereof, storage medium and processor

Info

Publication number: CN112361537A
Application number: CN202011320914.8A
Authority: CN
Inventors: 钟朝正; 倪毅; 李龙飞; 赵亮
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-02-12
Anticipated expiration: 2040-11-23
Also published as: CN112361537B

Abstract

The invention discloses an oil return control method and device of a multi-split system, the multi-split system, a storage medium and a processor, wherein the method comprises the following steps: under the condition that the multi-split air conditioner system runs, acquiring the accumulated running time of each running internal unit in the multi-split air conditioner system; determining whether more than one running internal machine in the multi-split air conditioning system reaches a set oil return condition according to the accumulated running time of each running internal machine in the multi-split air conditioning system; determining that the internal machines in the multi-split air conditioning system need to be returned under the condition that more than one running internal machine in the multi-split air conditioning system reaches the oil return condition; and controlling the oil-returning internal machine to return oil according to the determined oil-returning internal machine. According to the scheme, the oil return is performed on the inner machine which reaches the oil return condition, so that the output capacity requirement of the compressor is reduced, and the oil return energy consumption is saved.

Description

Multi-split air conditioning system and oil return control method and device thereof, storage medium and processor

Technical Field

The invention belongs to the technical field of multi-online systems, and particularly relates to an oil return control method and device for a multi-online system, the multi-online system, a storage medium and a processor, and in particular relates to an efficient oil return control method and device for the multi-online system, the storage medium and the processor.

Background

The multi-split central air conditioner is an air conditioning system in which one outdoor unit is connected with two or more indoor units through a pipe, namely a multi-split system. Multiple on-line systems are increasingly used in small and medium-sized buildings and some public buildings.

In related schemes, after a unit of a multi-split system runs for a period of time, refrigeration oil needs to be recovered from pipelines and indoor units of the multi-split system, so that damage or burnout of a compressor due to oil shortage is prevented. However, when the multi-split air conditioning system returns oil, all the internal machines need to be returned oil indiscriminately, so that the output capacity of the compressor is high in demand, and energy waste is caused.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention aims to provide an oil return control method and device of a multi-split system, the multi-split system, a storage medium and a processor, so as to solve the problems that the output capacity requirement of a compressor is large and energy waste is caused by indiscriminately returning oil to all internal machines during oil return of the multi-split system, and achieve the effects of reducing the output capacity requirement of the compressor and saving oil return energy consumption by returning oil to the internal machines meeting oil return conditions.

The invention provides an oil return control method of a multi-split system, which comprises the following steps: under the condition that the multi-split air conditioner system runs, acquiring the accumulated running time of each running internal unit in the multi-split air conditioner system; determining whether more than one running internal machine in the multi-split air conditioning system reaches a set oil return condition according to the accumulated running time of each running internal machine in the multi-split air conditioning system; determining that the internal machines in the multi-split air conditioning system need to be returned under the condition that more than one running internal machine in the multi-split air conditioning system reaches the oil return condition; and controlling the oil-returning internal machine to return oil according to the determined oil-returning internal machine.

In some embodiments, determining whether more than one operating indoor unit in the multi-split air-conditioning system reaches a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system includes: determining whether the accumulated running time of running internal machines in all running internal machines of the multi-online system is equal to set time or not; and if the accumulated running time of the running internal machines in all the running internal machines of the multi-online system is equal to the set time, determining that the running internal machines with the accumulated running time equal to the set time reach the oil return condition.

In some embodiments, determining whether more than one operating indoor unit in the multi-split air-conditioning system has reached a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system further includes: under the condition that the accumulated running time of the running internal machines is equal to the set time in all the running internal machines of the multi-split air-conditioning system, further determining whether the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system; the set coefficient is greater than 0 and less than 1; and if the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system, determining that the running internal machines with the accumulated running time larger than or equal to the set factor times of the set time also reach the oil return condition.

In some embodiments, in a case that more than one operating indoor unit in the multi-split air-conditioning system reaches the oil return condition, determining that the indoor units in all the indoor units in the multi-split air-conditioning system need oil return, includes: determining whether the number of the running internal machines which reach the oil return condition in the multi-split air conditioning system reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or whether the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system or not; if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; determining all the internal machines in the multi-split system as internal machines needing oil return; if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition does not reach a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; the capacity of the running internal machines which reach the oil return condition in the multi-split air conditioning system does not reach a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining that the running internal machine which reaches the oil return condition in the multi-split air conditioning system is an internal machine which needs oil return.

In some embodiments, controlling the oil-return-required inner machine to return oil according to the determined oil-return-required inner machine includes: if the internal machines needing oil return are all internal machines in the multi-split air-conditioning system, controlling all the internal machines in the multi-split air-conditioning system to carry out oil return in batches; and if the internal machine needing oil return is the running internal machine which reaches the oil return condition in the multi-split air-conditioning system, controlling the running internal machine which reaches the oil return condition in the multi-split air-conditioning system to return oil.

In some embodiments, all of the internal machines in the multi-split system include: the originally operated internal machine and the originally non-operated internal machine; controlling all internal machines in the multi-split system to return oil in batches, and the method comprises the following steps: controlling the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system to return oil preferentially; after oil return of the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system is finished, the internal machines which are operated originally in all the internal machines in the multi-split air conditioner system are controlled to return oil; under the condition that the internal machines which do not operate originally in all the internal machines in the multi-split air-conditioning system return oil, the throttle units of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system are controlled to be closed or the opening degree of the throttle units is reduced to a first set opening degree, and the rotating speed of the fans of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system is controlled to be reduced according to a set speed reduction mode.

In some embodiments, controlling the internal machines in the multi-split system that are not operated originally to return oil preferentially includes: according to the number or the capacity of the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system, the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system are batched according to a first set batching frequency, and then each batch of the internal machines which are not operated originally are controlled to return oil; and then controlling the internal machines which originally run in all the internal machines in the multi-online system to return oil, wherein the control method comprises the following steps: and according to the number or the capacity of the internal machines which originally operate in the multi-split air conditioner system, the internal machines which originally operate in the multi-split air conditioner system are batched according to a second set batching frequency, and then each batch of the internal machines which originally operate are controlled to return oil.

In some embodiments, in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, any of the controls to perform oil return includes: if the working mode of the multi-split system is a refrigeration mode, the working mode does not need to be switched; if the working mode of the multi-split air conditioning system is a heating mode, switching the working mode of the multi-split air conditioning system to a cooling mode; determining oil return frequency required by a compressor of the multi-split system in a refrigeration mode; executing an oil return action, namely: controlling the frequency of a compressor of the multi-split air conditioner system to rise to the oil return frequency required by the compressor, controlling the opening degree of the throttling unit of the internal unit entering an oil return program in the multi-split air conditioner system to increase to a second set opening degree, and controlling the opening degree of the throttling unit of the internal unit not entering the oil return degree to decrease to a third set opening degree; and if the time for executing the oil return action reaches the set oil return time, stopping executing the oil return action.

In some embodiments, determining a desired oil return frequency of a compressor of the multi-split system includes: under the condition that the compressor of the multi-split air conditioner system is one compressor, determining the oil return frequency required by the compressor of the multi-split air conditioner system according to the quantity and the capacity of all the internal machines; and under the condition that the compressors of the multi-split system are more than two compressors, determining the oil return frequency required by the compressors of the multi-split system according to the starting and stopping of different compressors in the more than two compressors.

In another aspect, the present invention provides an oil return control device for a multi-split air conditioning system, including: the acquisition unit is configured to acquire the accumulated running time of each running internal unit in the multi-split air-conditioning system under the condition that the multi-split air-conditioning system runs; the control unit is configured to determine whether more than one running internal machines in the multi-split air conditioning system reach set oil return conditions according to the accumulated running time of each running internal machine in the multi-split air conditioning system; the control unit is further configured to determine that the internal machines in the multi-split air conditioning system need to be returned to the oil when more than one running internal machine in the multi-split air conditioning system reaches the oil return condition; the control unit is further configured to control the oil-needing-returning internal machine to return oil according to the determined oil-needing-returning internal machine.

In some embodiments, the determining, by the control unit, whether more than one operating indoor unit in the multi-split air-conditioning system has reached a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system includes: determining whether the accumulated running time of running internal machines in all running internal machines of the multi-online system is equal to set time or not; and if the accumulated running time of the running internal machines in all the running internal machines of the multi-online system is equal to the set time, determining that the running internal machines with the accumulated running time equal to the set time reach the oil return condition.

In some embodiments, the determining, by the control unit, whether more than one operating indoor unit in the multi-split air-conditioning system has reached a set oil return condition according to an accumulated operating time of each operating indoor unit in the multi-split air-conditioning system further includes: under the condition that the accumulated running time of the running internal machines is equal to the set time in all the running internal machines of the multi-split air-conditioning system, further determining whether the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system; the set coefficient is greater than 0 and less than 1; and if the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system, determining that the running internal machines with the accumulated running time larger than or equal to the set factor times of the set time also reach the oil return condition.

In some embodiments, the determining, by the control unit, that there is an internal unit needing oil return in all internal units in the multi-split air-conditioning system when more than one operating internal unit in the multi-split air-conditioning system reaches the oil return condition includes: determining whether the number of the running internal machines which reach the oil return condition in the multi-split air conditioning system reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or whether the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system or not; if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; determining all the internal machines in the multi-split system as internal machines needing oil return; if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition does not reach a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; the capacity of the running internal machines which reach the oil return condition in the multi-split air conditioning system does not reach a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining that the running internal machine which reaches the oil return condition in the multi-split air conditioning system is an internal machine which needs oil return.

In some embodiments, the controlling unit, according to the determined oil-return-required internal machine, controls the oil-return-required internal machine to perform oil return, including: if the internal machines needing oil return are all internal machines in the multi-split air-conditioning system, controlling all the internal machines in the multi-split air-conditioning system to carry out oil return in batches; and if the internal machine needing oil return is the running internal machine which reaches the oil return condition in the multi-split air-conditioning system, controlling the running internal machine which reaches the oil return condition in the multi-split air-conditioning system to return oil.

In some embodiments, all of the internal machines in the multi-split system include: the originally operated internal machine and the originally non-operated internal machine; the control unit controls all the internal machines in the multi-split system to return oil in batches, and the control unit comprises: controlling the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system to return oil preferentially; after oil return of the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system is finished, the internal machines which are operated originally in all the internal machines in the multi-split air conditioner system are controlled to return oil; under the condition that the internal machines which do not operate originally in all the internal machines in the multi-split air-conditioning system return oil, the throttle units of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system are controlled to be closed or the opening degree of the throttle units is reduced to a first set opening degree, and the rotating speed of the fans of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system is controlled to be reduced according to a set speed reduction mode.

In some embodiments, the controlling unit controls an internal machine which is not operated originally in all internal machines in the multi-split air conditioning system to preferentially perform oil return, and the controlling unit includes: according to the number or the capacity of the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system, the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system are batched according to a first set batching frequency, and then each batch of the internal machines which are not operated originally are controlled to return oil; and then controlling the internal machines which originally run in all the internal machines in the multi-online system to return oil, wherein the control method comprises the following steps: and according to the number or the capacity of the internal machines which originally operate in the multi-split air conditioner system, the internal machines which originally operate in the multi-split air conditioner system are batched according to a second set batching frequency, and then each batch of the internal machines which originally operate are controlled to return oil.

In some embodiments, the controlling unit, in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, performs any control of performing oil return, including: if the working mode of the multi-split system is a refrigeration mode, the working mode does not need to be switched; if the working mode of the multi-split air conditioning system is a heating mode, switching the working mode of the multi-split air conditioning system to a cooling mode; determining oil return frequency required by a compressor of the multi-split system in a refrigeration mode; executing an oil return action, namely: controlling the frequency of a compressor of the multi-split air conditioner system to rise to the oil return frequency required by the compressor, controlling the opening degree of the throttling unit of the internal unit entering an oil return program in the multi-split air conditioner system to increase to a second set opening degree, and controlling the opening degree of the throttling unit of the internal unit not entering the oil return degree to decrease to a third set opening degree; and if the time for executing the oil return action reaches the set oil return time, stopping executing the oil return action.

In some embodiments, the determining, by the control unit, a desired oil return frequency of a compressor of the multi-split system includes: under the condition that the compressor of the multi-split air conditioner system is one compressor, determining the oil return frequency required by the compressor of the multi-split air conditioner system according to the quantity and the capacity of all the internal machines; and under the condition that the compressors of the multi-split system are more than two compressors, determining the oil return frequency required by the compressors of the multi-split system according to the starting and stopping of different compressors in the more than two compressors.

In accordance with another aspect of the present invention, there is provided a multi-split system, including: the oil return control device of the multi-split air conditioning system is characterized in that the oil return control device comprises a control unit.

In accordance with the foregoing method, in yet another aspect, the present invention provides a storage medium, where the storage medium includes a stored program, and when the program runs, the apparatus where the storage medium is located is controlled to execute the oil return control method of the multi-split system described above.

In accordance with the above method, a further aspect of the present invention provides a processor, where the processor is configured to execute a program, where the program executes the oil return control method of the multi-split system described above.

Therefore, according to the scheme of the invention, the oil return condition is set in the multi-split system, the running time and running state of different internal machines are judged, so that one internal machine or a plurality of internal machines reaching the oil return condition are determined, oil return is carried out on the internal machine or the plurality of internal machines reaching the oil return condition, the output capacity requirement of the compressor is reduced, and the oil return energy consumption is saved.

Furthermore, according to the scheme of the invention, when oil return is performed on one or more internal machines which reach the oil return condition, oil return is performed in a partial oil return or step-by-step oil return mode, so that the frequency of the compressor during single oil return can be reduced, the noise during oil return is reduced, and the influence on user experience caused by excessive noise at night is avoided.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic flow chart of an embodiment of an oil return control method of a multi-split air conditioning system according to the present invention;

fig. 2 is a schematic flow chart illustrating an embodiment of determining whether more than one operating internal machines in the multi-split air conditioning system reach a set oil return condition in the method of the present invention;

fig. 3 is a schematic flow chart of another embodiment of determining whether more than one operating indoor unit in the multi-split air conditioning system has reached the set oil return condition in the method of the present invention;

fig. 4 is a schematic flow chart of an embodiment of determining the internal machines needing oil return in all the internal machines in the multi-split system according to the method of the present invention;

fig. 5 is a schematic flow chart of an embodiment of controlling all internal machines in the multi-split system to perform oil return in batches in the method of the present invention;

FIG. 6 is a schematic flow chart illustrating an embodiment of control of oil return in the method of the present invention;

fig. 7 is a schematic structural diagram of an oil return control device of a multi-split system according to an embodiment of the invention;

fig. 8 is a flow diagram of an embodiment of a multi-split efficient oil return control method.

The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:

102-an obtaining unit; 104-control unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, an oil return control method for a multi-split air conditioning system is provided, as shown in fig. 1, which is a schematic flow chart of an embodiment of the method of the present invention. The oil return control method of the multi-split system can comprise the following steps: step S110 to step S140.

In step S110, in a case that the multi-split air conditioning system is operating, an accumulated operating time of each operating indoor unit in the multi-split air conditioning system is obtained.

In step S120, it is determined whether more than one operating indoor units in the multi-split air-conditioning system have reached a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system.

In some embodiments, a specific process of determining whether more than one operating indoor unit in the multi-split air-conditioning system has reached the set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system in step S120 may be referred to as the following exemplary description.

The following may further describe, with reference to a flowchart of an embodiment of determining whether more than one operating internal machine in the multi-split air-conditioning system has reached the set oil return condition in the method shown in fig. 2, a specific process of determining whether more than one operating internal machine in the multi-split air-conditioning system has reached the set oil return condition in step S120, where the specific process may include: step S210 and step S220.

And step S210, determining whether the accumulated running time of running internal machines in all running internal machines of the multi-online system is equal to the set time. The set time may be the set time T.

And step S220, if the accumulated running time of running internal machines in all running internal machines of the multi-online system is equal to the set time, determining that the running internal machines with the accumulated running time equal to the set time reach the oil return condition.

Specifically, the accumulated running time Ti of each internal machine is recorded, and i is a positive integer and represents the ith internal machine. And recording the accumulated operation time Ti of all the internal machines through a program or a storage component, wherein the recorded value is that the accumulated operation time Ti of each internal machine is T1, T2, … and Tn, and n is a positive integer. The method for judging whether each internal machine of the multi-split air conditioning system reaches the oil return condition is as follows: whether the accumulated operation time Ti reaches the set time T. When the multi-split air conditioner system normally operates and the accumulated operation time Ti of one or more internal machines reaches the set time T set by the oil return condition, the internal machines which reach the oil return condition are subjected to oil return.

In some embodiments, in step S120, a specific process of determining whether more than one operating indoor units in the multi-split air-conditioning system have reached a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system may also be referred to as the following exemplary description.

With reference to another embodiment flowchart of determining whether more than one operating indoor unit in the multi-split air-conditioning system has reached the set oil return condition in the method of the present invention shown in fig. 3, another specific process of determining whether more than one operating indoor unit in the multi-split air-conditioning system has reached the set oil return condition in step S120 is further described, and may include: step S310 and step S320.

Step S310, under the condition that the accumulated running time of the running internal machines is equal to the set time in all the running internal machines of the multi-split air-conditioning system, whether the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system is further determined. The other operation inner machines are the rest operation inner machines except the operation inner machine which reaches the oil return condition. The set coefficient is greater than 0 and less than 1, for example, the set coefficient may be 0.75.

Step S320, if the accumulated operation time of the operating indoor units in other operating indoor units of the multi-split air-conditioning system is greater than or equal to the set factor times of the set time, determining that the operating indoor units with the accumulated operation time greater than or equal to the set factor times of the set time have also reached the oil return condition.

Specifically, the accumulated running time Ti of other internal machines which do not reach the oil return condition is determined, and if the accumulated running time Ti of other internal machines which do not reach the oil return condition is not less than 0.75T, the internal machine with the accumulated running time Ti being not less than 0.75T is also marked as an oil return internal machine, so as to avoid the system from frequently entering an oil return program and improve the running stability of the system.

In step S130, in the case that more than one operating indoor unit in the multi-split air-conditioning system reaches the oil return condition, it is determined that the indoor units in all the indoor units in the multi-split air-conditioning system need to be returned to oil. And the internal machines which need oil return, namely the internal machines which need oil return in all the internal machines in the multi-split air-conditioning system.

In some embodiments, in step S130, when more than one operating indoor unit in the multi-split air-conditioning system reaches the oil return condition, a specific process of returning the indoor units in all the indoor units in the multi-split air-conditioning system to oil is determined, which may be referred to as the following exemplary description.

The following further describes, with reference to a schematic flow chart of an embodiment of determining the internal machines needing oil return in all the internal machines in the multi-split air-conditioning system in the method shown in fig. 4, a specific process of determining the internal machines needing oil return in all the internal machines in the multi-split air-conditioning system in step S130, which may include: step S410 to step S430.

Step S410, determining whether the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or whether the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system. The first setting ratio and the second setting ratio may be the same or different, for example, 80% of the first setting ratio and the second setting ratio may be selected.

Step S420, if the number of the running internal machines in the multi-split air conditioning system reaching the oil return condition reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining all the internal machines in the multi-split system as internal machines needing oil return.

Step S430, if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition does not reach a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; the capacity of the running internal machines which reach the oil return condition in the multi-split air conditioning system does not reach a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining that the running internal machine which reaches the oil return condition in the multi-split air conditioning system is an internal machine which needs oil return.

Specifically, after one or more internal machines reach the oil return condition, the number or capacity of the internal machines is determined (whether the number is consistent with the number of all the internal machines or whether the capacity is consistent with the total capacity of the system) to determine whether the internal machines needing oil return are all the internal machines. If the number or the capacity of the internal machines needing oil return reaches 80% of the total number or the total capacity, the oil return can be carried out in batches according to the oil return of all the internal machines.

Therefore, whether oil return is carried out or not is judged by the oil return inner machine, oil return is carried out on a single or multiple inner machines through control, the problem that oil return existing in oil return of all the inner machines in related schemes is uncontrollable is solved, and the technical effect that the oil return inner machines are controllable is achieved.

In step S140, the oil-return-required internal machine is controlled to return oil according to the determined oil-return-required internal machine.

Specifically, conditions are set in the multi-split system, and oil return is performed on one or part of the internal machines, or the internal machines are subjected to alternate oil return actions. Through the judgment of the running time and running state of different internal machines, one or partial internal machines are returned oil in a targeted manner, the running frequency of the compressor during oil return can be reduced, the electric energy is saved, the high-frequency noise of the compressor is reduced, the use comfort is improved, and the problems of uncontrollable oil return, energy waste and overlarge noise in the multi-split oil return technology can be solved.

In some embodiments, in step S140, according to the determined oil-return-required internal machine, a specific process of oil return of the oil-return-required internal machine is controlled, where the specific process includes any one of the following oil return control processes:

the first oil return control process: and if the internal machines needing oil return are all the internal machines in the multi-split air-conditioning system, controlling all the internal machines in the multi-split air-conditioning system to carry out oil return in batches.

Specifically, if oil return is needed for all the internal machines of the multi-split system, all the internal machines are subjected to batch oil return according to the quantity or capacity.

The second oil return control process: and if the internal machine needing oil return is the running internal machine which reaches the oil return condition in the multi-split air-conditioning system, controlling the running internal machine which reaches the oil return condition in the multi-split air-conditioning system to return oil.

Specifically, if the multi-split air conditioning system needs oil return for part of the internal machines, the oil return operation is directly performed on the internal machines needing oil return. Preferably, if the number or the capacity of the inner machines needing oil return reaches 80% of the total number or the total capacity, the oil return can be carried out in batches according to the oil return of all the inner machines, for example, the oil return can be carried out on all the inner machines twice.

Therefore, the inner machines reaching the oil return condition are subjected to oil return, the output capacity requirement of the compressor during oil return is lower than that of the whole multi-split air conditioning system, the problem of high oil return energy consumption in oil return of all the inner machines in related schemes is solved, and the technical effect of saving electric energy is achieved.

In some embodiments, all of the internal machines in the multi-split system include: the originally operated internal machine and the originally non-operated internal machine.

With reference to a flow diagram of an embodiment of the method shown in fig. 5, which is used for controlling all the internal machines in the multi-split air conditioning system to perform oil return in batches, a specific process of controlling all the internal machines in the multi-split air conditioning system to perform oil return in batches will be further described, and the specific process may include: step S510 and step S520.

And step S510, controlling the internal machines which are not operated originally in all the internal machines in the multi-online system to preferentially return oil.

In some embodiments, the step S510 of controlling the internal machines not in operation in all the internal machines in the multi-split air-conditioning system to preferentially perform oil return includes: and according to the number or the capacity of the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system, after the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system are batched according to a first set batching frequency, controlling the internal machines which are not operated originally in each batch to return oil.

And step S520, after oil return of the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system is finished, controlling the internal machines which are operated originally in all the internal machines in the multi-split air conditioner system to return oil.

Under the condition that the internal machines which do not operate originally in all the internal machines in the multi-split air-conditioning system return oil, the throttle units of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system are controlled to be closed or the opening degree of the throttle units is reduced to a first set opening degree, and the rotating speed of the fans of the internal machines which operate originally in all the internal machines in the multi-split air-conditioning system is controlled to be reduced according to a set speed reduction mode.

Specifically, when oil is returned to all the internal machines, the oil can be preferentially returned to the internal machines which are not started, when the internal machines which are not started return oil, the electronic expansion valves of the internal machines which are started are closed or changed to be smaller in opening degree, and the rotating speed of the internal fans of the internal machines which are started is slowly reduced, so that the cold quantity or the heat quantity of the refrigerant in the indoor heat exchanger is utilized to the maximum extent to maintain the indoor environment temperature.

In some embodiments, the step S520 of controlling the internal machines, which are originally operated, in all the internal machines in the multi-split system to perform oil return again includes: and according to the number or the capacity of the internal machines which originally operate in the multi-split air conditioner system, the internal machines which originally operate in the multi-split air conditioner system are batched according to a second set batching frequency, and then each batch of the internal machines which originally operate are controlled to return oil.

Specifically, the oil return is performed m times by setting the number or total capacity of the internal machines needing oil return as α, and m is a positive integer. The quantity and the capacity during oil return are equally divided as much as possible until oil return of all the internal machines needing oil return is finished, so that the output capacity of the compressor is kept unchanged during oil return, and only the internal machine valves and the fan are adjusted.

Therefore, partial oil return or step-by-step oil return is carried out on the inner machine needing oil return, the frequency of the compressor during single oil return is lower than that during oil return of the whole machine, the problems of high frequency and high noise of the compressor during oil return in related schemes are solved, and the technical effect of reducing oil return noise is achieved.

In some embodiments, in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, any specific process of performing oil return control may be referred to in the following exemplary description.

The following further describes a specific process of controlling oil return by referring to a schematic flow chart of an embodiment of controlling oil return in the method of the present invention shown in fig. 6, and the specific process may include: step S610 to step S630.

Step S610, if the operating mode of the multi-split system is the cooling mode, the operating mode does not need to be switched. And if the working mode of the multi-split air conditioning system is a heating mode, switching the working mode of the multi-split air conditioning system to a cooling mode. And under the refrigeration mode, determining the oil return frequency required by the compressor of the multi-split system.

In some embodiments, the step S610 of determining the oil return frequency required by the compressor of the multi-split air conditioning system includes any one of the following determination situations:

the first determination case: and under the condition that the compressor of the multi-split air conditioner system is one compressor, determining the oil return frequency required by the compressor of the multi-split air conditioner system according to the quantity and the capacity of all the internal machines.

Specifically, when the output capacity of the compressor required by oil return to all the internal machine systems is W1, the frequency of the corresponding compressor is P1, the correction coefficient of the output capacity of the corresponding compressor is β 1, the total number or the total capacity of the internal machines is α, oil return is performed m times, the output capacity required by the compressor during partial oil return is W1 × β 1/m, and the frequency of the corresponding compressor is the oil return frequency P of the compressor.

Second determination case: and under the condition that the compressors of the multi-split system are more than two compressors, determining the oil return frequency required by the compressors of the multi-split system according to the starting and stopping of different compressors in the more than two compressors.

Specifically, if the multi-split air conditioning system is a multi-compressor multi-split air conditioning system, the oil return frequency can be controlled by starting and stopping different compressors, so that oil return of part of the internal machines is achieved, noise is reduced, electric energy is saved, and the like. The multi-compressor multi-split air conditioning system can ensure that the output efficiency of the compressor is highest under the condition of consistent total oil return output capacity through the output capacity ratio of different compressors, and can achieve the purposes of reducing the frequency of the compressor, reducing noise and saving energy.

Step S620, an oil return operation is performed, that is: and controlling the frequency of the compressor of the multi-split air conditioner system to rise to the oil return frequency required by the compressor, and controlling the opening degree of the throttling unit of the internal unit entering an oil return program in the multi-split air conditioner system to increase to a second set opening degree and the opening degree of the throttling unit of the internal unit not entering the oil return degree to decrease to a third set opening degree.

In step S630, if the time for performing the oil return operation reaches the set oil return time, the oil return operation is stopped.

Specifically, when the main mode of the multi-split air-conditioning system is the refrigeration mode, the number and the capacity of the internal machines entering the oil return program are calculated to obtain the oil return frequency P required by the compressor, and the smaller the number and the capacity of the internal machines are, the lower the required oil return frequency is. And (3) raising the frequency of the compressor to P, keeping the electronic expansion valve of the oil return internal machine at a larger opening L, closing the electronic expansion valve of the internal machine or keeping the electronic expansion valve at a smaller opening J when the oil return internal machine does not return, ending the oil return action when the set running time t is operated, and entering oil return programs of other internal machines or recovering normal control. When the master mode of the multi-split system is the heating mode, the multi-split system is controlled to enter the cooling mode, and oil return is performed according to the oil return action of the multi-split system in the cooling mode.

Through a large number of tests, the technical scheme of the embodiment is adopted, the oil return condition is set in the multi-split system, the running time and running state of different internal machines are judged, so that one internal machine or a plurality of internal machines reaching the oil return condition are determined, oil is returned to the internal machine or the plurality of internal machines reaching the oil return condition, and the internal machines reaching the oil return condition are returned, so that the output capacity requirement of the compressor is reduced, and the oil return energy consumption is saved.

According to the embodiment of the invention, the oil return control device of the multi-split system corresponding to the oil return control method of the multi-split system is also provided. Referring to fig. 7, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The oil return control device of the multi-split system may include: an acquisition unit 102 and a control unit 104.

The obtaining unit 102 is configured to obtain, when the multiple split-line system is running, an accumulated running time of each running internal machine in the multiple split-line system. The specific functions and processes of the acquiring unit 102 are referred to in step S110.

And the control unit 104 is configured to determine whether more than one operating indoor unit in the multi-split air-conditioning system reaches a set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system. The specific function and processing of the control unit 104 are referred to in step S120.

In some embodiments, the determining, by the control unit 104, whether more than one operating indoor units in the multi-split air-conditioning system have reached the set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system includes:

the control unit 104 is further specifically configured to determine whether an accumulated operation time of any of the operating internal machines of the multi-split air conditioning system is equal to a set time. The set time may be the set time T. The specific functions and processes of the control unit 104 are also referred to in step S210.

The control unit 104 is further specifically configured to determine that the operating indoor unit with the accumulated operating time equal to the set time has reached the oil return condition if the accumulated operating time of the operating indoor units in all the operating indoor units of the multi-split air conditioning system is equal to the set time. The specific functions and processes of the control unit 104 are also referred to in step S220.

In some embodiments, the determining, by the control unit 104, whether more than one operating indoor units in the multi-split air-conditioning system have reached the set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air-conditioning system further includes:

the control unit 104 is further specifically configured to, in a case that the accumulated operating time of the operating indoor units in all the operating indoor units of the multi-split air-conditioning system is equal to the set time, further determine whether the accumulated operating time of the operating indoor units in other operating indoor units of the multi-split air-conditioning system is greater than or equal to a set factor of the set time. The other operation inner machines are the rest operation inner machines except the operation inner machine which reaches the oil return condition. The set coefficient is greater than 0 and less than 1, for example, the set coefficient may be 0.75. The specific functions and processes of the control unit 104 are also referred to in step S310.

The control unit 104 is further specifically configured to determine that, if, among other running indoor units of the multi-split air-conditioning system, the accumulated running time of the running indoor units is greater than or equal to the set factor times of the set time, the running indoor units with the accumulated running time greater than or equal to the set factor times of the set time have also reached the oil return condition. The specific functions and processes of the control unit 104 are also referred to in step S320.

The control unit 104 is further configured to determine that, when more than one operating indoor unit in the multi-split air-conditioning system reaches the oil return condition, the indoor units in the multi-split air-conditioning system need to be returned to the oil. And the internal machines which need oil return, namely the internal machines which need oil return in all the internal machines in the multi-split air-conditioning system. The specific function and processing of the control unit 104 are also referred to in step S130.

In some embodiments, the determining, by the control unit 104, that there is an internal unit needing oil return in all internal units in the multi-split air-conditioning system when more than one running internal unit in the multi-split air-conditioning system reaches the oil return condition includes:

the control unit 104 is further specifically configured to determine whether the number of operating internal machines in the multi-split air conditioning system, which have reached the oil return condition, reaches a first set proportion of the total number of all internal machines in the multi-split air conditioning system; or whether the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system. The first setting ratio and the second setting ratio may be the same or different, for example, 80% of the first setting ratio and the second setting ratio may be selected. The specific functions and processes of the control unit 104 are also referred to in step S410.

The control unit 104 is further specifically configured to, if the number of operating internal machines in the multi-split air conditioning system that have reached the oil return condition reaches a first set proportion of the total number of all internal machines in the multi-split air conditioning system; or the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system. And determining all the internal machines in the multi-split system as internal machines needing oil return. The specific function and processing of the control unit 104 are also referred to in step S420.

The control unit 104 is further specifically configured to, if the number of operating internal machines in the multi-split air conditioning system that have reached the oil return condition does not reach a first set proportion of the total number of all internal machines in the multi-split air conditioning system; the capacity of the running internal machines which reach the oil return condition in the multi-split air conditioning system does not reach a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining that the running internal machine which reaches the oil return condition in the multi-split air conditioning system is an internal machine which needs oil return. The specific functions and processes of the control unit 104 are also referred to in step S430.

The control unit 104 is further configured to control the oil-return-required internal machine to perform oil return according to the determined oil-return-required internal machine. The specific function and processing of the control unit 104 are also referred to in step S140.

In some embodiments, the control unit 104, according to the determined oil-return-required internal machine, controls the oil-return-required internal machine to perform oil return, including any one of the following oil return control processes:

the first oil return control process: the control unit 104 is specifically configured to control all the internal machines in the multi-split air-conditioning system to perform oil return in batches if the internal machines needing oil return are all the internal machines in the multi-split air-conditioning system.

The second oil return control process: the control unit 104 is specifically configured to control the operating indoor unit in the multi-split air-conditioning system that has reached the oil return condition to return oil if the indoor unit that needs oil return is the operating indoor unit in the multi-split air-conditioning system that has reached the oil return condition.

In some embodiments, all of the internal machines in the multi-split system include: the originally operated internal machine and the originally non-operated internal machine. The control unit 104 controls all the internal machines in the multi-split system to perform oil return in batches, and includes:

the control unit 104 is specifically configured to control the internal machines that are not operated originally in all the internal machines in the multi-split air conditioning system to preferentially perform oil return. The specific functions and processes of the control unit 104 are also referred to in step S510.

In some embodiments, the controlling unit 104 controls, of all the internal machines in the multi-split air conditioner system, an internal machine that is not operated originally to perform oil return preferentially, where the controlling unit includes: the control unit 104 is further specifically configured to, according to the number or the capacity of the internal machines in the multi-split air-conditioning system that have not operated originally, control each batch of the internal machines that have not operated originally to return oil after the internal machines in the multi-split air-conditioning system that have not operated originally are batched by a first set batching number of times.

The control unit 104 is further specifically configured to control the internal machines that are not operated in the multi-split air conditioning system to perform oil return after oil return of the internal machines that are not operated in the multi-split air conditioning system is completed. The specific functions and processes of the control unit 104 are also referred to in step S520.

In some embodiments, the controlling unit 104 is specifically further configured to control an internal unit, which is originally operated, of all internal units in the multi-split system to perform oil return, and includes: the control unit 104 is further specifically configured to, according to the number or capacity of the internal machines that are originally operated in all the internal machines in the multi-split air-conditioning system, control each batch of the internal machines that are originally operated in the multi-split air-conditioning system to perform oil return after the internal machines that are originally operated in all the internal machines in the multi-split air-conditioning system are batched according to a second set batching frequency.

In some embodiments, the controlling unit 104, in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, performs any one of the control of oil return, including:

the control unit 104 is further specifically configured to not switch the working mode if the working mode of the multi-split air-conditioning system is the cooling mode. And if the working mode of the multi-split air conditioning system is a heating mode, switching the working mode of the multi-split air conditioning system to a cooling mode. And under the refrigeration mode, determining the oil return frequency required by the compressor of the multi-split system. The specific functions and processes of the control unit 104 are also referred to in step S610.

In some embodiments, the control unit 104, determining the oil return frequency required by the compressor of the multi-split system, includes any one of the following determination conditions:

the first determination case: the control unit 104 is further specifically configured to, in a case that the compressor of the multi-split air conditioning system is one compressor, determine an oil return frequency required by the compressor of the multi-split air conditioning system according to the number and the capacity of all the internal machines.

Second determination case: the control unit 104 is further specifically configured to, when the compressors of the multi-split air conditioning system are more than two compressors, determine the oil return frequency required by the compressors of the multi-split air conditioning system according to the start and stop of different compressors of the more than two compressors.

The control unit 104 is specifically further configured to perform an oil return action, that is: and controlling the frequency of the compressor of the multi-split air conditioner system to rise to the oil return frequency required by the compressor, and controlling the opening degree of the throttling unit of the internal unit entering an oil return program in the multi-split air conditioner system to increase to a second set opening degree and the opening degree of the throttling unit of the internal unit not entering the oil return degree to decrease to a third set opening degree. The specific functions and processes of the control unit 104 are also referred to in step S620.

The control unit 104 is further specifically configured to stop performing the oil return operation if the time for performing the oil return operation reaches the set oil return time. The specific function and processing of the control unit 104 are also referred to in step S630.

Since the processes and functions implemented by the apparatus of this embodiment substantially correspond to the embodiments, principles and examples of the method shown in fig. 1 to fig. 6, the description of this embodiment is not detailed, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.

Through a large number of tests, the technical scheme of the invention is adopted, when one or more internal machines reaching the oil return condition are subjected to oil return, the oil return is carried out in a partial oil return or step-by-step oil return mode, so that the frequency of the compressor during single oil return can be reduced, the noise during oil return is reduced, and the influence on user experience caused by over-high noise at night is avoided.

According to the embodiment of the invention, the multi-split system corresponding to the oil return control device of the multi-split system is also provided. The multi-split system may include: the oil return control device of the multi-split air conditioning system is characterized in that the oil return control device comprises a control unit.

And executing an oil return action after the unit of the multi-split air conditioning system operates for a certain time, such as 4 hours. At this time, generally, the compressor is operated at a high frequency, and all the internal machine valves are opened to a certain opening degree, so that the refrigerant in the machine set is rapidly circulated, and the refrigerant oil outside the compressor is brought back into the compressor.

In the oil return process, all the indoor units return oil indiscriminately, so that the compressor needs high output to enable the refrigerant to rapidly circulate in the whole system, and energy waste is caused. In addition, if it is at night when the user is asleep, it may cause a problem of excessive noise and even cause after-sales complaints.

Therefore, when the multi-split air conditioner system returns oil, all the internal machines are returned oil indiscriminately, and the problems of uncontrollable oil return, energy waste, overlarge noise and the like exist.

In some embodiments, the scheme of the invention provides a multi-split efficient oil return control method, and conditions are set in a multi-split system, so that oil return is performed on one or part of internal machines, or alternate oil return actions are performed on the internal machines. Through the judgment of the running time and running state of different internal machines, one or partial internal machines are returned oil in a targeted manner, the running frequency of the compressor during oil return can be reduced, the electric energy is saved, the high-frequency noise of the compressor is reduced, the use comfort is improved, and the problems of uncontrollable oil return, energy waste and overlarge noise in the multi-split oil return technology can be solved.

The running state refers to whether the internal machine is started or not, and oil return is preferentially carried out on the internal machine which is not in the running state in the process of judging whether the internal machine is in the oil return state or not. For example, the internal unit A is in a shutdown state and has a continuous operation time T_ANot less than 0.75T, when the inner machines B and C are in running state, the inner machine B reaches the oil return time T and the running time of the inner machine C is judged by T_CNot less than 0.75T; if all oil return internal machines need to be subjected to oil return in batches at the moment, the oil return is preferentially performed on the oil return A, and the situations that the oil return of the first batch of B + C and the oil return of the second batch of A do not occur.

According to the scheme, whether oil return is performed or not is judged for the oil return internal machines, and oil return is performed on one or more internal machines through control, so that the problem that oil return for all the internal machines in related schemes is uncontrollable is solved, and the technical effect that the oil return internal machines are controllable is achieved.

According to the scheme, the inner machines which reach the oil return condition are subjected to oil return, so that the output capacity requirement of the compressor during oil return is lower than that of the whole multi-split air conditioning system, the problem of high oil return energy consumption in the oil return of all the inner machines in related schemes is solved, and the technical effect of saving electric energy is achieved.

According to the scheme provided by the invention, partial oil return or step-by-step oil return is carried out on the internal machine needing oil return, so that the frequency of the compressor during single oil return is lower than that during oil return of the whole machine, the problems of high frequency and high noise of the compressor during oil return in related schemes are solved, and the technical effect of reducing oil return noise is achieved.

The following describes an exemplary implementation of the scheme of the present invention with reference to the example shown in fig. 8.

Fig. 8 is a flow diagram of an embodiment of a multi-split efficient oil return control method. As shown in fig. 8, a flow of the multi-split efficient oil return control method includes:

step 1, recording the accumulated running time Ti of each internal machine, wherein i is a positive integer and represents the ith internal machine.

Specifically, the accumulated operation time Ti of all the internal machines is recorded through a program or a storage component, and the recorded value is set as the accumulated operation time Ti of each internal machine being T1, T2, … and Tn, where n is a positive integer. The method for judging whether each internal machine of the multi-split air conditioning system reaches the oil return condition is as follows: whether the accumulated operation time Ti reaches the set time T.

And 2, when the multi-split system normally operates and the accumulated operation time Ti of one or more internal machines reaches the set time T set by the oil return condition, returning oil to the internal machines which reach the oil return condition.

Preferably, the accumulated running time Ti of other internal machines which do not reach the oil return condition is determined, and if the accumulated running time Ti of other internal machines which do not reach the oil return condition is greater than or equal to 0.75T, the internal machine with the accumulated running time Ti greater than or equal to 0.75T is also marked as an oil return internal machine, so as to avoid the system from frequently entering the oil return program and improve the running stability of the system.

And 3, after one or more internal machines reach the oil return condition, judging the number or capacity of the internal machines (whether the number is consistent with the number of all the internal machines or whether the capacity is consistent with the total capacity of the system) so as to judge whether the internal machines needing oil return are all the internal machines.

And if all the internal machines of the multi-split system need oil return, performing batch oil return on all the internal machines according to the quantity or the capacity.

Preferably, when all the internal machines are subjected to oil return, oil can be preferentially returned to the originally-started internal machine, when the originally-started internal machine returns oil, the electronic expansion valve of the originally-started internal machine is closed or changed to a smaller opening degree, and the rotating speed of the internal fan of the originally-started internal machine is slowly reduced, so that the cold quantity or the heat quantity of a refrigerant in the indoor heat exchanger is utilized to the maximum extent to maintain the indoor environment temperature.

And 4, on the basis of the judgment in the step 3, if the multi-split air conditioner system needs oil return for part of the internal machines, directly performing oil return operation on the internal machines needing oil return. Preferably, if the number or capacity of the internal machines needing oil return reaches 80% of the total number or the total capacity (namely the total number or the total capacity of all the internal machines), the oil return can be carried out in batches according to the oil return of all the internal machines, for example, the oil return can be carried out on all the internal machines in two times.

Wherein, batch oil return includes: if oil return is divided into two times, capacity division is taken as an example, the total capacity of the internal machines with the oil return twice is consistent or similar as much as possible, and the internal machines which are not started are preferentially subjected to oil return. For example, the system has a/B/C/D4 internal machines, the capacities of which are 1/2/3/4, wherein the ACD internal machines are running and all reach the oil return condition, the B internal machines do not reach the oil return condition, but the capacities of the ACD internal machines reach 80% of the total capacity, the oil return is performed on the whole system, that is, the B internal machines are also subjected to oil return. At the moment, oil return with equal capacity is carried out for two times, and the internal unit which is not started up preferentially returns oil, so that the first oil return internal unit is B + C, and the second oil return internal unit is A + D.

Purpose of batch oil return: 1. the frequency of the press with single oil return is reduced, and the noise during oil return can be reduced; 2. for the compressor, generally, the efficiency curve is a parabola, the efficiency in high-frequency operation is lower than that in medium-frequency operation, and the high-frequency operation of the compressor is also beneficial to energy conservation when oil return is avoided.

Step 5, oil return action:

when the main mode of the multi-split system is a refrigeration mode, the number and the capacity of the internal machines entering the oil return program are calculated to obtain the oil return frequency P required by the compressor, and the smaller the number and the capacity of the internal machines are, the lower the required oil return frequency is. And (4) increasing the frequency of the compressor to P, keeping the electronic expansion valve of the oil return internal machine at a larger opening L, closing the electronic expansion valve of the internal machine or keeping the electronic expansion valve at a smaller opening J when the oil return internal machine does not return, ending the oil return action when the set running time t is operated, and judging to enter other internal machine oil return programs or recovering normal control according to the steps 3 and 4.

The capacity of the internal machine is commonly called several machines, each capacity is provided with a corresponding dial, and the external machine can be connected with the internal machine through a communication line and then read.

Setting the output capacity of compressor to W when oil returns to all the indoor unit systems₁Corresponding to compressor frequency P₁At this time, the correction coefficient corresponding to the output capacity of the compressor is beta₁If the total number or the total capacity of the internal machines is alpha, oil return is performed m times, and the output capacity required by the compressor during partial oil return is W₁×β₁And m, wherein the corresponding compressor frequency at this time is the compressor oil return frequency P.

Specifically, the capacity of the once oil return internal machine can be compared with the total capacity, and oil return can be performed through preset oil return frequencies of different compressors. Namely:

1. if the total capacity alpha of the inner machine with single oil return_iAlpha is less than or equal to 40 percent, and the oil return frequency is set to be P₁；

2. If the total capacity of the internal machine with single oil return is 40 percent alpha < alpha_iAlpha is less than or equal to 60 percent, and oil return frequency is setIs P₂。

3. If the total capacity of the internal machine with single oil return is 60 percent alpha < alpha_iAlpha is not more than 80 percent, and the oil return frequency is set to be P₃. Wherein P is₁＜P₂＜P₃. And when the total amount of the oil return internal machine is more than 80%, the whole system is returned in batches, so that the total capacity of the single oil return internal machine cannot exceed 80%.

When the master mode of the multi-split system is the heating mode, the multi-split system is controlled to enter the cooling mode, and oil return is performed according to the oil return action of the multi-split system in the cooling mode.

In the above embodiment, the oil return frequency is determined by PID adjustment. Because the performance curves of different compressors are slightly different, the optimum performance can be achieved by different combinations of the frequencies of different compressors under the same output capacity. Therefore, if the multi-split air conditioning system is a multi-compressor multi-split air conditioning system, the oil return frequency can be controlled by starting and stopping different compressors, so that the oil return of part of the internal machines is achieved, the noise is reduced, the electric energy is saved, and the like.

The multi-compressor multi-split air conditioning system can ensure that the output efficiency of the compressor is highest under the condition of consistent total oil return output capacity through the output capacity ratio of different compressors, and can achieve the purposes of reducing the frequency of the compressor, reducing noise and saving energy.

Since the processing and functions implemented by the multi-split system of the present embodiment substantially correspond to the embodiment, the principle and the example of the apparatus shown in fig. 7, the description of the present embodiment is not detailed, and reference may be made to the related description in the foregoing embodiments, which is not repeated herein.

Through a large number of tests, the technical scheme of the invention is adopted, and the conditions are set in the multi-split system, so that one or part of the internal machines are subjected to oil return, or the internal machines are subjected to alternate oil return action, the oil return process of the multi-split system is controllable, and the multi-split system is low in energy consumption and low in noise.

According to an embodiment of the present invention, there is also provided a storage medium corresponding to an oil return control method of a multi-split air-conditioning system, where the storage medium includes a stored program, and when the program runs, a device in which the storage medium is located is controlled to execute the oil return control method of the multi-split air-conditioning system.

Since the processing and functions implemented by the storage medium of this embodiment substantially correspond to the embodiments, principles, and examples of the methods shown in fig. 1 to fig. 6, details are not described in the description of this embodiment, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.

Through a large number of tests, the technical scheme provided by the invention can be used for specifically returning oil to one or part of the internal machines by judging the running time and running state of different internal machines, so that the running frequency of the compressor during oil returning can be reduced, the electric energy is saved, the high-frequency noise of the compressor is reduced, and the use comfort is improved.

According to an embodiment of the present invention, there is also provided a processor corresponding to an oil return control method of a multi-split air conditioning system, where the processor is configured to execute a program, where the program executes the oil return control method of the multi-split air conditioning system when running.

Since the processing and functions implemented by the processor of this embodiment substantially correspond to the embodiments, principles, and examples of the methods shown in fig. 1 to fig. 6, details are not described in the description of this embodiment, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.

Through a large number of tests, the technical scheme of the invention is adopted, the oil return condition is set in the multi-split air conditioner system, the running time and running state of different internal machines are judged, so that one internal machine or a plurality of internal machines reaching the oil return condition are determined, the oil return of the internal machine or the plurality of internal machines reaching the oil return condition is carried out, the oil return process of the multi-split air conditioner system is controllable, the output capacity requirement on a compressor is low, and the oil return energy is saved.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An oil return control method of a multi-split air conditioning system is characterized by comprising the following steps:

under the condition that the multi-split air conditioner system runs, acquiring the accumulated running time of each running internal unit in the multi-split air conditioner system;

determining whether more than one running internal machine in the multi-split air conditioning system reaches a set oil return condition according to the accumulated running time of each running internal machine in the multi-split air conditioning system;

determining that the internal machines in the multi-split air conditioning system need to be returned under the condition that more than one running internal machine in the multi-split air conditioning system reaches the oil return condition;

and controlling the oil-returning internal machine to return oil according to the determined oil-returning internal machine.

2. The oil return control method of a multi-split air-conditioning system according to claim 1, wherein determining whether more than one operating indoor unit in the multi-split air-conditioning system has reached a set oil return condition according to an accumulated operating time of each operating indoor unit in the multi-split air-conditioning system comprises:

determining whether the accumulated running time of running internal machines in all running internal machines of the multi-online system is equal to set time or not;

and if the accumulated running time of the running internal machines in all the running internal machines of the multi-online system is equal to the set time, determining that the running internal machines with the accumulated running time equal to the set time reach the oil return condition.

3. The oil return control method of a multi-split air conditioning system according to claim 2, wherein determining whether more than one operating indoor unit in the multi-split air conditioning system has reached a set oil return condition according to an accumulated operating time of each operating indoor unit in the multi-split air conditioning system further comprises:

under the condition that the accumulated running time of the running internal machines is equal to the set time in all the running internal machines of the multi-split air-conditioning system, further determining whether the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system; the set coefficient is greater than 0 and less than 1;

and if the accumulated running time of the running internal machines is larger than or equal to the set factor times of the set time in other running internal machines of the multi-split air-conditioning system, determining that the running internal machines with the accumulated running time larger than or equal to the set factor times of the set time also reach the oil return condition.

4. The oil return control method of a multi-split air-conditioning system according to any one of claims 1 to 3, wherein in a case where more than one operating indoor unit in the multi-split air-conditioning system reaches the oil return condition, determining that the indoor unit in the multi-split air-conditioning system needs to be returned to the oil, includes:

determining whether the number of the running internal machines which reach the oil return condition in the multi-split air conditioning system reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or whether the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system or not;

if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; or the capacity of the running internal machines in the multi-split air conditioning system which reach the oil return condition reaches a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; determining all the internal machines in the multi-split system as internal machines needing oil return;

if the number of the running internal machines in the multi-split air conditioning system which reach the oil return condition does not reach a first set proportion of the total number of all the internal machines in the multi-split air conditioning system; the capacity of the running internal machines which reach the oil return condition in the multi-split air conditioning system does not reach a second set proportion of the total capacity of all the internal machines in the multi-split air conditioning system; and determining that the running internal machine which reaches the oil return condition in the multi-split air conditioning system is an internal machine which needs oil return.

5. The oil return control method of a multi-split system according to claim 4, wherein the step of controlling the oil return internal machine to return oil according to the determined oil return internal machine to be returned comprises the steps of:

if the internal machines needing oil return are all internal machines in the multi-split air-conditioning system, controlling all the internal machines in the multi-split air-conditioning system to carry out oil return in batches;

and if the internal machine needing oil return is the running internal machine which reaches the oil return condition in the multi-split air-conditioning system, controlling the running internal machine which reaches the oil return condition in the multi-split air-conditioning system to return oil.

6. The oil return control method of a multi-split air conditioning system according to claim 5, wherein all the indoor units in the multi-split air conditioning system comprise: the originally operated internal machine and the originally non-operated internal machine; controlling all internal machines in the multi-split system to return oil in batches, and the method comprises the following steps:

controlling the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system to return oil preferentially;

after oil return of the internal machines which are not operated originally in all the internal machines in the multi-split air conditioner system is finished, the internal machines which are operated originally in all the internal machines in the multi-split air conditioner system are controlled to return oil;

7. The oil return control method of a multi-split air conditioning system according to claim 6, wherein controlling the internal machines, which are not operated originally, of all the internal machines in the multi-split air conditioning system to preferentially perform oil return comprises:

according to the number or the capacity of the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system, the internal machines which are not operated originally in all the internal machines in the multi-split air-conditioning system are batched according to a first set batching frequency, and then each batch of the internal machines which are not operated originally are controlled to return oil;

and then controlling the internal machines which originally run in all the internal machines in the multi-online system to return oil, wherein the control method comprises the following steps:

and according to the number or the capacity of the internal machines which originally operate in the multi-split air conditioner system, the internal machines which originally operate in the multi-split air conditioner system are batched according to a second set batching frequency, and then each batch of the internal machines which originally operate are controlled to return oil.

8. The oil return control method of a multi-split air conditioning system according to claim 7, wherein in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, any of the controls to perform oil return includes:

if the working mode of the multi-split system is a refrigeration mode, the working mode does not need to be switched; if the working mode of the multi-split air conditioning system is a heating mode, switching the working mode of the multi-split air conditioning system to a cooling mode; determining oil return frequency required by a compressor of the multi-split system in a refrigeration mode;

executing an oil return action, namely: controlling the frequency of a compressor of the multi-split air conditioner system to rise to the oil return frequency required by the compressor, controlling the opening degree of the throttling unit of the internal unit entering an oil return program in the multi-split air conditioner system to increase to a second set opening degree, and controlling the opening degree of the throttling unit of the internal unit not entering the oil return degree to decrease to a third set opening degree;

and if the time for executing the oil return action reaches the set oil return time, stopping executing the oil return action.

9. The oil return control method of a multi-split system as claimed in claim 8, wherein determining a desired oil return frequency of a compressor of the multi-split system comprises:

under the condition that the compressor of the multi-split air conditioner system is one compressor, determining the oil return frequency required by the compressor of the multi-split air conditioner system according to the quantity and the capacity of all the internal machines;

and under the condition that the compressors of the multi-split system are more than two compressors, determining the oil return frequency required by the compressors of the multi-split system according to the starting and stopping of different compressors in the more than two compressors.

10. The utility model provides an oil return controlling means of multi-split system which characterized in that includes:

the acquisition unit is configured to acquire the accumulated running time of each running internal unit in the multi-split air-conditioning system under the condition that the multi-split air-conditioning system runs;

the control unit is configured to determine whether more than one running internal machines in the multi-split air conditioning system reach set oil return conditions according to the accumulated running time of each running internal machine in the multi-split air conditioning system;

the control unit is further configured to determine that the internal machines in the multi-split air conditioning system need to be returned to the oil when more than one running internal machine in the multi-split air conditioning system reaches the oil return condition;

the control unit is further configured to control the oil-needing-returning internal machine to return oil according to the determined oil-needing-returning internal machine.

11. The oil return control device of a multi-split air conditioning system according to claim 10, wherein the determining, by the control unit, whether more than one operating indoor unit in the multi-split air conditioning system has reached the set oil return condition according to the accumulated operating time of each operating indoor unit in the multi-split air conditioning system includes:

12. The oil return control device of a multi-split air conditioning system according to claim 11, wherein the control unit determines whether more than one operating indoor unit in the multi-split air conditioning system has reached a set oil return condition according to an accumulated operating time of each operating indoor unit in the multi-split air conditioning system, and further includes:

13. The oil return control device of a multi-split air conditioning system according to any one of claims 10 to 12, wherein the determining, by the control unit, that the indoor units of the multi-split air conditioning system need to be returned in case that more than one operating indoor unit of the multi-split air conditioning system reaches the oil return condition includes:

14. The oil return control device of a multi-split system according to claim 13, wherein the control unit controls the oil return internal machine to return oil according to the determined oil return internal machine, and includes:

15. The oil return control device of a multi-split air conditioning system according to claim 14, wherein all the indoor units in the multi-split air conditioning system comprise: the originally operated internal machine and the originally non-operated internal machine; the control unit controls all the internal machines in the multi-split system to return oil in batches, and the control unit comprises:

16. The oil return control device of a multi-split air conditioning system according to claim 15, wherein the control unit controls the internal machines, which are not operated originally, of all the internal machines in the multi-split air conditioning system to preferentially perform oil return, and includes:

17. The oil return control device of a multi-split air conditioning system as claimed in claim 16, wherein the control unit performs any control of oil return in controlling the running internal machines in the multi-split air conditioning system that have reached the oil return condition to perform oil return, controlling each batch of internal machines that have not run originally to perform oil return, and controlling each batch of internal machines that have run originally to perform oil return, and the control unit includes:

18. The oil return control device of a multi-split system as claimed in claim 17, wherein the control unit determining a desired oil return frequency of compressors of the multi-split system comprises:

19. A multiple on-line system, comprising: the oil return control device of a multi-split system as claimed in any one of claims 10 to 18.

20. A storage medium, characterized in that the storage medium includes a stored program, wherein when the program is executed, an apparatus in which the storage medium is located is controlled to execute the oil return control method of a multi-split system according to any one of claims 1 to 9.

21. A processor, characterized in that the processor is configured to execute a program, wherein the program executes the oil return control method of a multi-split system according to any one of claims 1 to 9.