CN115950067A

CN115950067A - Air conditioning system, oil return control method and device thereof, and storage medium

Info

Publication number: CN115950067A
Application number: CN202211550589.3A
Authority: CN
Inventors: 滕天凤; 焦华超; 武连发; 高晗; 金孟孟
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-04-11

Abstract

The invention discloses an oil return control method and device of an air conditioning system, the air conditioning system and a storage medium, wherein the method comprises the following steps: determining the ratio of the total capacity of the indoor unit to the total capacity of the outdoor unit of the air conditioning system, and recording the ratio as the ratio of the air conditioning system; determining whether the ratio of the air conditioning system is less than or equal to a set ratio: if so, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode according to the accumulated running time of the air conditioning system; otherwise, grouping all the indoor units of the air conditioning system according to the accumulated running time of the air conditioning system to obtain more than two groups of indoor units, and controlling the more than two groups of indoor units of the air conditioning system to return oil according to a set grouping oil return mode. According to the scheme, when the air conditioning system returns oil, the number of the indoor units participating in oil return is adjusted according to the proportion of the air conditioning system, so that lubricating oil in the indoor units smoothly returns to the outdoor unit, normal operation of the air conditioning system is guaranteed, and damage is avoided.

Description

Air conditioning system, oil return control method and device thereof and storage medium

Technical Field

The invention belongs to the technical field of air conditioning systems, and particularly relates to an oil return control method and device of an air conditioning system, the air conditioning system and a storage medium, in particular to an oil return control method and device of a high-proportion air conditioning system, the air conditioning system and the storage medium.

Background

In the operation process of the air conditioning system, lubricating oil is easy to store in an indoor unit and a long connecting pipe (namely a long refrigerant pipe between the indoor unit and an outdoor unit) of the air conditioning system. In order to guarantee the reliability of the air conditioning system, after the air conditioning system runs for a period of time, oil return needs to be carried out on all indoor units, namely, lubricating oil in the indoor units and the long connecting pipes of the air conditioning system is brought back to the outdoor unit of the air conditioning system, so that the normal running of the air conditioning system is ensured, and the unit where the air conditioning system is located is not damaged.

With the progress of science and technology, more indoor units can be matched with the air conditioning system; however, the higher the air conditioning system ratio (i.e., the ratio of the total capacity of the indoor units to the total capacity of the outdoor units), the slower the flow rate of the refrigerant flowing through each indoor unit in the air conditioning system. When the air conditioning system needs oil return control, the speed of a refrigerant flowing through the indoor unit is low, and lubricating oil stored in the indoor unit cannot be completely brought back to the outdoor unit, so that the outdoor unit lacks lubricating oil, a unit where the air conditioning system is located cannot normally operate, and even the unit where the air conditioning system is located is damaged.

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

Disclosure of Invention

The invention aims to provide an oil return control method and device of an air conditioning system, the air conditioning system and a storage medium, aiming at the air conditioning system with a large number of indoor units, the flow rate of refrigerant flowing through each indoor unit is low, and lubricating oil stored in the indoor units cannot be brought back to the outdoor unit during oil return operation, so that the outdoor unit is lack of lubricating oil, and the air conditioning system cannot normally operate or even be damaged.

The invention provides an oil return control method of an air conditioning system, wherein the air conditioning system is provided with an indoor unit and an outdoor unit; the number of the indoor units is more than two, and the number of the outdoor units is more than one; the oil return control method of the air conditioning system comprises the following steps: acquiring the sum of the capacities of all indoor units of the air conditioning system, and recording the sum as the total capacity of the indoor units of the air conditioning system; acquiring the sum of the capacities of all outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system; acquiring the accumulated running time of the air conditioning system; determining the ratio of the total capacity of the indoor units of the air-conditioning system to the total capacity of the outdoor units of the air-conditioning system, and recording the ratio as the ratio of the air-conditioning system; determining whether the ratio of the air conditioning system is less than or equal to a set ratio; if the proportion of the air-conditioning system is determined to be smaller than or equal to the set proportion, controlling all indoor units of the air-conditioning system to return oil according to the set normal oil return mode according to the accumulated running time of the air-conditioning system; and if the proportion of the air-conditioning system is determined to be larger than the set proportion, grouping all the indoor units of the air-conditioning system according to the accumulated running time of the air-conditioning system to obtain more than two groups of indoor units, and controlling the more than two groups of indoor units of the air-conditioning system to return oil according to the set grouping oil return mode.

In some embodiments, controlling oil return of all indoor units of the air conditioning system according to a set normal oil return mode according to the accumulated running time of the air conditioning system includes: determining whether the accumulated operation time of the air conditioning system reaches a first set time; if the accumulated running time of the air conditioning system is determined to reach the first set time, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode; after oil return is completed to all indoor units of the air-conditioning system according to the set normal oil return mode, all indoor units of the air-conditioning system are controlled to recover to the running state running before oil return, and the running state running is right, the accumulated running time of the air-conditioning system is cleared and then returned to acquire again the accumulated running time of the air-conditioning system, and under the condition that the ratio of the air-conditioning system is less than or equal to the set ratio, the accumulated running time of the air-conditioning system is controlled according to the acquired again the oil return of all indoor units of the air-conditioning system according to the set normal oil return mode.

In some embodiments, controlling oil return of all indoor units of the air conditioning system according to a set normal oil return mode includes: if the running state of an indoor unit in all the indoor units of the air-conditioning system before oil return is the running state in the refrigeration mode, when the indoor unit is controlled to return oil according to a set normal oil return mode, the running state of the indoor unit needs to be controlled to maintain the running state of the indoor unit in the refrigeration mode; if the running state of the indoor unit before oil return in all the indoor units of the air-conditioning system is the running state in the heating mode, when the indoor unit is controlled to return oil according to the set normal oil return mode, the running state of the indoor unit needs to be controlled to be converted into the running state of the indoor unit in the cooling mode; if the running state of the indoor unit before oil return in all the indoor units of the air conditioning system is shutdown, when the indoor unit is controlled to return oil according to a set normal oil return mode, the indoor unit needs to be controlled to be started, and then the running state of the indoor unit is controlled to be the running state of the indoor unit in a refrigeration mode.

In some embodiments, grouping all indoor units of the air conditioning system to obtain two or more groups of indoor units according to the accumulated running time of the air conditioning system, and controlling the two or more groups of indoor units of the air conditioning system to return oil according to a set grouping oil return mode includes: determining whether the accumulated running time of the air conditioning system reaches a second set time; if the accumulated running time of the air conditioning system reaches the second set time, grouping all indoor units of the air conditioning system according to the capacity of all indoor units of the air conditioning system or the quantity of all indoor units of the air conditioning system to obtain more than two groups of indoor units, recording the groups of indoor units as a first group of indoor units to an nth group of indoor units, wherein n is a positive integer greater than or equal to 2; controlling a first group of indoor units in all indoor units of the air-conditioning system to return oil according to a set group oil return mode, and controlling a second group of indoor units to an nth group of indoor units in all indoor units of the air-conditioning system to stop; when the oil return time of a first group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the first group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a second group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop; when the oil return time of a second group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the second group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a third group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop; by analogy, after the nth group of indoor units in all the indoor units of the air-conditioning system complete oil return, the operation states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are controlled to be restored to the operation state before oil return and reset, and then the operation state is returned to obtain the accumulated operation time of the air-conditioning system again, and under the condition that the ratio of the air-conditioning system is greater than the set ratio, all the indoor units of the air-conditioning system are grouped again to obtain more than two groups of indoor units according to the obtained accumulated operation time of the air-conditioning system again, and the oil return of the more than two groups of indoor units of the air-conditioning system is controlled according to the set grouping oil return mode; the grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air conditioning system last time.

In some embodiments, controlling oil return of a first group of indoor units among all indoor units of the air conditioning system according to a set group oil return mode includes: if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is the running state in the refrigeration mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to maintain the running state of the indoor units in the refrigeration mode; if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is the running state in the heating mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to be converted into the running state of the indoor units in the cooling mode, and fans of the group of indoor units are controlled to be stopped; if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is a shutdown state, when the group of indoor units are controlled to return oil according to a set grouping oil return mode, the group of indoor units are controlled to be started, a throttling device of the air-conditioning system is controlled to be started, and a fan of the group of indoor units is controlled to be shut down.

In another aspect, the present invention provides an oil return control device for an air conditioning system, wherein the air conditioning system comprises an indoor unit and an outdoor unit; the number of the indoor units is more than two, and the number of the outdoor units is more than one; the oil return control device of the air conditioning system comprises: the acquisition unit is configured to acquire the sum of the capacities of all indoor units of the air conditioning system and record the sum as the total capacity of the indoor units of the air conditioning system; acquiring the sum of the capacities of all outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system; acquiring the accumulated running time of the air conditioning system; the control unit is configured to determine the ratio of the total capacity of indoor units of the air conditioning system to the total capacity of outdoor units of the air conditioning system, and the ratio is recorded as the ratio of the air conditioning system; the control unit is further configured to determine whether a ratio of the air conditioning system is less than or equal to a set ratio; the control unit is further configured to control oil return of all indoor units of the air conditioning system according to a set normal oil return mode according to the accumulated running time of the air conditioning system if the proportion of the air conditioning system is determined to be smaller than or equal to a set proportion; the control unit is further configured to group all the indoor units of the air conditioning system into more than two groups of indoor units according to the accumulated running time of the air conditioning system if the proportion of the air conditioning system is determined to be larger than the set proportion, and control the more than two groups of indoor units of the air conditioning system to return oil according to the set group oil return mode.

In some embodiments, the controlling unit, according to the accumulated running time of the air conditioning system, controls all indoor units of the air conditioning system to return oil according to a set normal oil return mode, including: determining whether the accumulated running time of the air conditioning system reaches a first set time; if the accumulated running time of the air conditioning system is determined to reach the first set time, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode; and after all indoor units of the air conditioning system finish oil return according to a set normal oil return mode, controlling all indoor units of the air conditioning system to recover to the running state running before oil return, clearing the accumulated running time of the air conditioning system, returning to obtain the accumulated running time of the air conditioning system again, and controlling all indoor units of the air conditioning system to return oil according to the set normal oil return mode according to the obtained accumulated running time of the air conditioning system when the ratio of the air conditioning system is less than or equal to the set ratio.

In some embodiments, the controlling unit controls oil return of all indoor units of the air conditioning system according to a set normal oil return mode, and includes: if the running state of an indoor unit in all the indoor units of the air-conditioning system before oil return is the running state in the refrigeration mode, when the indoor unit is controlled to return oil according to a set normal oil return mode, the running state of the indoor unit needs to be controlled to maintain the running state of the indoor unit in the refrigeration mode; if the running state of the indoor unit before oil return in all the indoor units of the air conditioning system is the running state in the heating mode, when the indoor unit is controlled to return oil according to a set normal oil return mode, the running state of the indoor unit needs to be controlled to be converted into the running state of the indoor unit in the cooling mode; if the running state of the indoor units in all the indoor units of the air-conditioning system before oil return is shutdown, when the indoor units are controlled to return oil according to a set normal oil return mode, the indoor units need to be controlled to be started, and then the running state of the indoor units is controlled to be the running state of the indoor units in a refrigeration mode.

In some embodiments, the control unit, according to the accumulated running time of the air conditioning system, groups all indoor units of the air conditioning system into two or more groups, and controls the two or more groups of indoor units of the air conditioning system to return oil according to a set group oil return mode, includes: determining whether the accumulated running time of the air conditioning system reaches a second set time; if the accumulated running time of the air conditioning system reaches second set time, grouping all indoor units of the air conditioning system according to the capacity of all indoor units of the air conditioning system or the quantity of all indoor units of the air conditioning system to obtain more than two groups of indoor units, recording the groups as a first group of indoor units to an nth group of indoor units, wherein n is a positive integer greater than or equal to 2; controlling a first group of indoor units in all indoor units of the air-conditioning system to return oil according to a set group oil return mode, and controlling a second group of indoor units to an nth group of indoor units in all indoor units of the air-conditioning system to stop; under the condition that the oil return time of a first group of indoor units in all indoor units of the air-conditioning system reaches preset grouped oil return time according to a set grouped oil return mode, the first group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a second group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in a refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop; when the oil return time of a second group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the second group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a third group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; controlling the indoor units which do not participate in the oil return to stop; in this analogy, after the nth group of indoor units in all the indoor units of the air-conditioning system complete oil return, the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are considered to complete oil return, the running states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are controlled to be restored to the running state running before oil return, the accumulated running time of the air-conditioning system is reset, then the running state is returned to obtain the accumulated running time of the air-conditioning system again, and under the condition that the proportion of the air-conditioning system is greater than the set proportion, all the indoor units of the air-conditioning system are grouped again according to the newly obtained accumulated running time of the air-conditioning system to obtain more than two groups of indoor units, and the more than two groups of indoor units of the air-conditioning system are controlled to return oil according to the set grouping oil return mode; the grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air conditioning system last time.

In some embodiments, the controlling unit, controlling a first group of indoor units among all indoor units of the air conditioning system to return oil according to a set group oil return mode, includes: if the running state of a first group of indoor units in all the indoor units of the air conditioning system before oil return is the running state in the refrigeration mode, the running state of the group of indoor units needs to be controlled to maintain the running state of the indoor units in the refrigeration mode when the group of indoor units are controlled to return oil according to the set grouping oil return mode; if the running state of a first group of indoor units in all the indoor units of the air conditioning system before oil return is the running state in the heating mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to be converted into the running state of the indoor units in the cooling mode, and fans of the group of indoor units are controlled to stop; if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is a shutdown state, when the group of indoor units are controlled to return oil according to a set grouping oil return mode, the group of indoor units are controlled to be started, a throttling device of the air-conditioning system is controlled to be started, and a fan of the group of indoor units is controlled to be shut down.

In accordance with another aspect of the present invention, there is provided an air conditioning system including: the oil return control device of the air conditioning system.

In accordance with the above method, a further aspect of the present invention provides a storage medium, where the storage medium includes a stored program, and when the program runs, the device where the storage medium is located is controlled to execute the oil return control method of the air conditioning system.

Therefore, according to the scheme of the invention, by determining the ratio of the air-conditioning system, if the ratio of the air-conditioning system is less than or equal to the set ratio, more than two groups of indoor units are controlled to participate in oil return simultaneously when the air-conditioning system returns oil; if the proportion of the air conditioning system is greater than the set proportion, when the air conditioning system returns oil, all indoor units in the air conditioning system are evenly divided into more than two groups (preferably two groups) according to the capacity or the number, different groups of indoor units in the more than two groups of indoor units are controlled to participate in the oil return in different orders, so that the purpose that the more than two groups of indoor units participate in the oil return in different time is achieved, the number of the indoor units participating in the oil return in each time in the more than two groups of indoor units is adjusted to meet the requirement of the flow rate of refrigerant returning oil of the indoor units in the high proportion air conditioning system, and the lubricating oil in the indoor units smoothly returns to the outdoor units.

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 flowchart of an oil return control method of an air conditioning system according to an embodiment of the present invention;

fig. 2 is a schematic flow chart illustrating an embodiment of controlling oil return of all indoor units according to a set normal oil return mode according to the accumulated running time of the air conditioning system in the method of the present invention;

fig. 3 is a schematic flow chart illustrating an embodiment of controlling more than two groups of indoor units grouped into groups to return oil according to a set grouping oil return mode according to the accumulated operation time of the air conditioning system in the method of the present invention;

fig. 4 is a schematic structural diagram of an oil return control device of an air conditioning system according to an embodiment of the present invention;

fig. 5 is a flowchart illustrating an oil return control method of a high-ratio air conditioning system according to an embodiment of the present invention.

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

102-an acquisition 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 obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

In consideration of the fact that the number of indoor units in the high-ratio air conditioning system is large, the flow rate of refrigerant flowing through each indoor unit in the air conditioning system is low, and when a unit where the air conditioning system is located performs oil return operation, lubricating oil stored in the indoor units cannot be brought back to the outdoor units, so that the outdoor units lack lubricating oil, the unit where the air conditioning system is located cannot normally operate, and even the unit where the air conditioning system is located is damaged. Therefore, the scheme of the invention provides an oil return control method of an air conditioning system, in particular to an oil return control method of a high-proportion air conditioning system, so that lubricating oil in indoor units smoothly returns to an outdoor unit by adjusting the number of the indoor units participating in oil return according to the proportion of the air conditioning system when the air conditioning system returns oil, the normal operation of the air conditioning system is ensured, and the damage is avoided.

According to an embodiment of the present invention, an oil return control method for an 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 air conditioning system is provided with an indoor unit and an outdoor unit. The number of the indoor units is more than two, and the number of the outdoor units is more than one. The oil return control method of the air conditioning system comprises the following steps: step S110 to step S150.

In step S110, the sum of the capacities of all indoor units of the air conditioning system is obtained and recorded as the total capacity of the indoor units of the air conditioning system. And acquiring the sum of the capacities of all the outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system. And acquiring the accumulated running time of the air conditioning system.

At step S120, a ratio of a total indoor unit capacity of the air conditioning system to a total outdoor unit capacity of the air conditioning system is determined, and is recorded as a ratio of the air conditioning system.

At step S130, it is determined whether the air conditioning system is at a stoichiometric ratio less than or equal to a set stoichiometric ratio (e.g., set stoichiometric ratio a).

In step S140, if it is determined that the ratio of the air conditioning system is less than or equal to the set ratio, oil return of all indoor units of the air conditioning system is controlled according to the accumulated running time of the air conditioning system, so as to control oil return of all indoor units of the air conditioning system according to the set normal oil return mode under the condition that the air conditioning system needs oil return, thereby meeting the requirement of the refrigerant flow rate for oil return of indoor units in the high-ratio air conditioning system, enabling the lubricating oil in the indoor units to smoothly return to the outdoor unit, and ensuring normal operation of the unit where the air conditioning system is located.

In some embodiments, in step S140, a specific process of oil return of all indoor units of the air conditioning system in a set normal oil return mode is controlled according to the accumulated operation time of the air conditioning system, which is described in the following exemplary description.

With reference to the flowchart of fig. 2 showing an embodiment of controlling all the indoor units to return oil according to the set normal oil return mode according to the accumulated operation time of the air conditioning system in the method of the present invention, a specific process of controlling all the indoor units to return oil according to the set normal oil return mode according to the accumulated operation time of the air conditioning system in step S140 is further described, which includes: step S210 to step S230.

In step S210, it is determined whether the accumulated operation time of the air conditioning system reaches a first set time (e.g., a first set time T1).

And step S220, if the accumulated running time of the air conditioning system is determined to reach the first set time, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode. Of course, if it is determined that the accumulated running time of the air conditioning system does not reach the first set time, continuously controlling all indoor units of the air conditioning system to maintain the current running state.

And step S230, after all the indoor units of the air-conditioning system finish oil return according to a set normal oil return mode, controlling all the indoor units of the air-conditioning system to recover to the running state running before oil return, clearing the accumulated running time of the air-conditioning system, returning to obtain the accumulated running time of the air-conditioning system again, and controlling all the indoor units of the air-conditioning system to return oil according to the obtained accumulated running time of the air-conditioning system according to the set normal oil return mode under the condition that the ratio of the air-conditioning system is less than or equal to the set ratio. The oil return of all indoor units of the air conditioning system is completed according to a set normal oil return mode, and the oil return of all indoor units of the air conditioning system can be considered to be completed under the condition that the oil return time of all indoor units of the air conditioning system reaches a set normal oil return time according to the set normal oil return mode.

Specifically, fig. 5 is a flowchart illustrating an oil return control method of a high-ratio air conditioning system according to an embodiment. As shown in fig. 5, the oil return control method for a high-ratio air conditioning system according to the present invention includes:

step 1, determining the ratio of the air conditioning system and recording the ratio as the system ratio. The proportion of the air conditioning system refers to the percentage of the ratio of the sum of all indoor unit capacities to the sum of all outdoor unit capacities of the air conditioning system. The ratio of the multi-split air-conditioning system is about 130% at most, and the high ratio is that the sum of the capacities of all indoor units and the sum of the capacities of outdoor units exceeds 130%, such as 200%.

Step 2, judging whether the system ratio of the air-conditioning system is less than or equal to a set ratio A: if yes, executing step 3, otherwise executing step 4. Wherein, the setting ratio A is generally about 130%.

And 3, if the system proportion of the air-conditioning system is less than or equal to the set proportion A, controlling the air-conditioning system to normally return oil, namely controlling all indoor units of the air-conditioning system to participate in oil return at the same time, so that the lubricating oil in the indoor units smoothly returns to the outdoor unit, ensuring the normal operation of the air-conditioning system and avoiding damage.

Specifically, when the system ratio of the air conditioning system is less than or equal to the set ratio a, the number of the indoor units in the air conditioning system is x, and in this case, the flow rate of the refrigerant flowing through each indoor unit is high, and if oil return operation is performed, the lubricating oil can be brought back to the outdoor unit. Therefore, all indoor units of the air-conditioning system are controlled to participate in oil return at the same time, so that lubricating oil in the indoor units smoothly returns to the outdoor unit, normal operation of the air-conditioning system is guaranteed, and damage is avoided. Since the number of the corresponding indoor units changes when the capacities of the outdoor units in the air conditioning system are different, the number x of the indoor units changes along with the change of the capacity of the outdoor unit, and the minimum value of the number x of the indoor units is 2.

In some embodiments, in step S220, controlling oil return of all indoor units of the air conditioning system according to a set normal oil return mode, including a normal oil return process in any one of the following cases:

normal oil return process in the first case: if the running state of the indoor unit before oil return in all the indoor units of the air conditioning system is the running state in the refrigeration mode, when the indoor unit is controlled to return oil according to the set normal oil return mode, the running state of the indoor unit needs to be controlled to maintain the running state of the indoor unit in the refrigeration mode.

Normal oil return process in the second case: if the running state of the indoor unit before oil return in all the indoor units of the air conditioning system is the running state in the heating mode, when the indoor unit is controlled to return oil according to the set normal oil return mode, the running state of the indoor unit needs to be controlled to be converted into the running state of the indoor unit in the cooling mode.

Normal oil return process in the third case: if the running state of the indoor units in all the indoor units of the air-conditioning system before oil return is shutdown, when the indoor units are controlled to return oil according to a set normal oil return mode, the indoor units need to be controlled to be started, and then the running state of the indoor units is controlled to be the running state of the indoor units in a refrigeration mode.

Specifically, as shown in fig. 5, the oil return control method for a high-ratio air conditioning system according to the present invention further includes: in step 3, when the system ratio of the air conditioning system is less than or equal to the set ratio A, controlling all indoor units of the air conditioning system to participate in oil return at the same time, specifically: when the accumulated operation time of the unit where the air conditioning system is located reaches the first set time T1 and the air conditioning system needs oil return, the air conditioning system controls all indoor units to participate in oil return operation according to a normal oil return mode. All indoor units participate in oil return operation according to an oil return mode in the following table.

Current state of indoor unit	During oil return of air conditioning systemOperating state
		Refrigeration mode	Maintaining current mode operation
Heating mode	Operation in switched cooling mode
		Shutdown	Operation in the on-refrigeration mode

The first setting time T1 is generally greater than 4 hours, but different air conditioning systems may set different first setting times T1.

At step S150, if it is determined that the ratio of the air conditioning system is greater than the set ratio, grouping all indoor units of the air conditioning system into more than two groups according to the accumulated running time of the air conditioning system, and controlling the more than two groups of indoor units of the air conditioning system to return oil according to the set grouping oil return mode, so that under the condition that the air conditioning system needs oil return, the more than two groups of indoor units of the air conditioning system are controlled to return oil according to the set grouping oil return mode, thereby meeting the refrigerant flow rate requirement for oil return of the indoor units in the high ratio air conditioning system, enabling the lubricating oil in the indoor units to smoothly return to the outdoor units, and ensuring normal operation of the unit where the air conditioning system is located.

According to the oil return control method of the high-proportion system, when the proportion of the outdoor unit to the indoor unit of the air-conditioning system exceeds a certain proportion, the number of the indoor units participating in oil return is controlled, the requirement of the flow rate of the refrigerant returning to the indoor unit in the high-proportion air-conditioning system is met, the lubricating oil in the indoor unit smoothly returns to the outdoor unit, and the normal operation of the unit where the air-conditioning system is located is ensured. Specifically, in an air conditioning system with a high ratio (such as a multi-split air conditioning system), when a unit where the air conditioning system is located performs oil return operation, the indoor units are equally divided into 2 parts according to capacity or number, and each part of the indoor units sequentially participates in oil return to meet the requirement of the flow rate of refrigerant returning to the indoor units, so that lubricating oil in the indoor units smoothly returns to the outdoor units, the normal operation of the air conditioning system is ensured, and damage is avoided.

In some embodiments, in step S150, according to the accumulated operation time of the air conditioning system, all the indoor units of the air conditioning system are grouped into two or more groups of indoor units, and a specific process of oil return of the two or more groups of indoor units of the air conditioning system according to a set grouped oil return mode is controlled, which is described in the following exemplary description.

With reference to the flowchart of fig. 3 showing an embodiment of the method of the present invention, which controls the two or more groups of indoor units grouped together according to the accumulated operating time of the air conditioning system to return oil according to the set grouped oil return mode, further described is a specific process of controlling the two or more groups of indoor units grouped together according to the accumulated operating time of the air conditioning system to return oil according to the set grouped oil return mode in step S150, including: step S310 to step S360.

In step S310, it is determined whether the accumulated operation time of the air conditioning system reaches a second set time (e.g., a second set time T2).

Step S320, if the accumulated running time of the air conditioning system is determined to reach the second set time, grouping all the indoor units of the air conditioning system according to the capacity of all the indoor units of the air conditioning system or the quantity of all the indoor units of the air conditioning system to obtain more than two groups of indoor units, and recording the groups as a first group of indoor units to an nth group of indoor units, wherein n is a positive integer greater than or equal to 2. Of course, if it is determined that the accumulated running time of the air conditioning system does not reach the second set time, continuously controlling all indoor units of the air conditioning system to maintain the current running state.

And step S330, controlling a first group of indoor units in all indoor units of the air-conditioning system to return oil according to a set grouping oil return mode, and controlling a second group of indoor units to an nth group of indoor units in all indoor units of the air-conditioning system to stop.

Step S340, when the oil return time of the first group of indoor units in all indoor units of the air conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, considering that the first group of indoor units in all indoor units of the air conditioning system complete oil return, and after controlling the second group of indoor units in all indoor units of the air conditioning system to be started, controlling the operation state of the group of indoor units to be the operation state of the group of indoor units in the refrigeration mode, so as to control the group of indoor units to return oil. And controlling the indoor unit which does not participate in the oil return to stop.

Step S350, when the oil return time of the second group of indoor units in all indoor units of the air conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, considering that the second group of indoor units in all indoor units of the air conditioning system complete oil return, and controlling the operation state of the group of indoor units to be the operation state of the group of indoor units in the refrigeration mode after controlling the third group of indoor units in all indoor units of the air conditioning system to be started, so as to control the group of indoor units to return oil. And controlling the indoor unit which does not participate in the oil return to stop.

And S360, repeating the steps until the nth group of indoor units in all the indoor units of the air-conditioning system complete oil return, controlling the running states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system to recover to the running state running before oil return, clearing the accumulated running time of the air-conditioning system, returning to obtain the accumulated running time of the air-conditioning system again, and grouping all the indoor units of the air-conditioning system again to obtain more than two groups of indoor units according to the newly obtained accumulated running time of the air-conditioning system under the condition that the ratio of the air-conditioning system is greater than the set ratio, and controlling the more than two groups of indoor units of the air-conditioning system to return oil according to the set grouping oil return mode. The grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air-conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air-conditioning system last time.

Specifically, as shown in fig. 5, the oil return control method for a high-ratio air conditioning system according to the present invention further includes: and 4, if the system ratio of the air conditioning system is larger than the set ratio A, averagely dividing all the indoor units into two groups according to the capacity or the quantity, marking the two groups as a first group of indoor units and a second group of indoor units, and controlling the two groups of indoor units to participate in oil return in sequence. And after the oil return is finished, controlling the air conditioning system to recover the operation mode before the oil return.

Specifically, when the system ratio of the air conditioning system is greater than the set ratio a, if all the indoor units perform oil return operation, the flow rate of the refrigerant flowing through each indoor unit is slow under the condition, and the lubricating oil stored in the indoor units may not be brought back to the outdoor unit, so that the unit where the air conditioning system is located cannot normally operate. At the moment, the air conditioning system is in a high-proportion state, a large number of connected indoor units are arranged, copper pipes of the air conditioning system are lengthened, the refrigerant flowing through each indoor unit is reduced, the flow rate is also slowed, and therefore lubricating oil is difficult to bring back to the outdoor unit when oil return runs. If only half of the indoor units return oil during operation, the proportion of the air conditioning system is reduced, the refrigerant distributed to each indoor unit is increased, the copper pipe through which the refrigerant flows is shortened, the flow rate is increased, and the lubricating oil can be brought back to the outdoor unit. Therefore, when the accumulated running time of the air conditioning system is larger than the second set time T2, the air conditioning system needs to carry out oil return control, the air conditioning system is divided into two groups according to the capacity or the number of the indoor units, and the ratio of the capacity of each group of indoor units is smaller than the set ratio A. And then, controlling the two groups of indoor units to participate in oil return in sequence. And after the oil return is finished, controlling the air conditioning system to recover the operation mode before the oil return. The second setting time T2 may be the same as the first setting time T1, for example, the same oil return timing determination criterion is set for air conditioning systems of the same manufacturer. Certainly, the second setting time T2 may be different from the second setting time T1, so that the oil return time judgment criteria of the low-ratio air conditioning system and the high-ratio air conditioning system are different for the air conditioning system of the same manufacturer, which is beneficial to more accurately controlling the oil return time of the low-ratio air conditioning system and the oil return time of the high-ratio air conditioning system, and ensures the oil return reliability and the operation reliability of the air conditioning system.

In some embodiments, the step S330 is to control oil return of a first group of indoor units among all indoor units of the air conditioning system according to a set group oil return mode, and includes a group oil return process in any one of the following cases:

the grouping oil return process in the first case: if the operation state of the first group of indoor units in all the indoor units of the air conditioning system before oil return is the operation state in the refrigeration mode, the operation state of the group of indoor units needs to be controlled to maintain the operation state of the indoor units in the refrigeration mode when the group of indoor units are controlled to return oil according to the set grouping oil return mode.

The grouping oil return process in the second case: if the running state of a first group of indoor units in all the indoor units of the air conditioning system before oil return is the running state in the heating mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to be converted into the running state of the indoor units in the cooling mode, and fans of the group of indoor units are controlled to stop.

Grouping oil return process under the third condition: if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is a shutdown state, when the group of indoor units are controlled to return oil according to a set grouping oil return mode, the group of indoor units are controlled to be started, a throttling device of the air-conditioning system is controlled to be started, and a fan of the group of indoor units is controlled to be shut down.

Specifically, as shown in fig. 5, the oil return control method for a high-ratio air conditioning system according to the present invention further includes: in step 4, the specific process of controlling the two groups of indoor units to participate in oil return in sequence is as follows:

step 41, the air conditioning system starts a first group of indoor units to participate in oil return operation, and the first group of indoor units return oil according to the control mode in the following table:

current state of indoor unit	Running state of air conditioning system during oil return
		Refrigeration mode	Maintaining current mode operation
Heating mode	Turning to a refrigeration mode, stopping the fan
		Shutdown	Opening the electronic expansion valve and stopping the fan

And under the condition that the first group of indoor units participate in oil return operation, the second group of indoor units are all shut down. Of course, when the oil returns to the second group of indoor units, the oil returns according to the oil return mode of the first group of indoor units.

And 42, when the oil return time of the first group of indoor units reaches the preset oil return time t (such as 5-10 min), ending oil return of the first group of indoor units, starting the second group of indoor units to participate in oil return operation, and stopping the first group of indoor units completely. And when the oil return time of the second group of indoor units reaches the preset oil return time t, ending the oil return operation of the air conditioning system, recovering the operation mode of the air conditioning system before oil return, and recovering the operation mode of all the indoor units before oil return.

And after oil return is finished, clearing the accumulated running time of the air conditioning system, recalculating new accumulated running time, and regrouping all indoor units when oil return is performed next time. Here, all the indoor units may or may not be grouped again when oil return is performed next time, because a complete oil return is performed once when all the indoor units participate in oil return, and the final result is that the refrigerant flow rate is increased by grouping, so that the lubricating oil returns to the outdoor unit. When the oil is grouped again, the result of the grouping again needs to be ensured, which is different from the result of the previous grouping, so that all indoor units can participate in oil return alternately in the oil return grouping process, and the oil return effect is improved. Therefore, under the high-proportion air-conditioning system, the flow velocity of the refrigerant in the indoor unit during oil return is increased according to the number of the indoor units participating in oil return control, so that the flow velocity requirement of the refrigerant returning to the indoor unit in the high-proportion air-conditioning system is met, the lubricating oil in the indoor unit smoothly returns to the outdoor unit, the normal operation of the air-conditioning system is ensured, and the damage is avoided.

By adopting the technical scheme of the embodiment, through determining the ratio of the air conditioning system, if the ratio of the air conditioning system is less than or equal to the set ratio, more than two groups of indoor units are controlled to participate in oil return simultaneously when the air conditioning system returns oil. If the proportion of the air conditioning system is greater than the set proportion, when the air conditioning system returns oil, all indoor units in the air conditioning system are evenly divided into more than two groups (preferably two groups) according to the capacity or the number, different groups of indoor units in the more than two groups of indoor units are controlled to participate in the oil return in different orders, so that the purpose that the more than two groups of indoor units participate in the oil return in different time is achieved, the number of the indoor units participating in the oil return in each time in the more than two groups of indoor units is adjusted to meet the requirement of the flow rate of refrigerant returning oil of the indoor units in the high proportion air conditioning system, and the lubricating oil in the indoor units smoothly returns to the outdoor units.

According to the embodiment of the invention, the oil return control device of the air conditioning system corresponding to the oil return control method of the air conditioning system is also provided. Referring to fig. 4, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The air conditioning system is provided with an indoor unit and an outdoor unit. The number of the indoor units is more than two, and the number of the outdoor units is more than one. The oil return control device of the air conditioning system comprises: an acquisition unit 102 and a control unit 104.

The obtaining unit 102 is configured to obtain a sum of capacities of all indoor units of the air conditioning system, which is recorded as a total capacity of the indoor units of the air conditioning system. And acquiring the sum of the capacities of all the outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system. And acquiring the accumulated running time of the air conditioning 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 a ratio of the total capacity of the indoor units of the air conditioning system to the total capacity of the outdoor units of the air conditioning system, which is recorded as the ratio of the air conditioning system. The specific function and processing of the control unit 104 are referred to in step S120.

The control unit 104 is further configured to determine whether the air conditioning system air conditioning ratio is less than or equal to a set ratio (e.g., set ratio a). The specific function and processing of the control unit 104 are also referred to in step S130.

The control unit 104 is further configured to, if it is determined that the ratio of the air conditioning system is less than or equal to a set ratio, control all indoor units of the air conditioning system to return oil according to a set normal oil return mode according to the accumulated running time of the air conditioning system, so that all indoor units of the air conditioning system are controlled to return oil according to the set normal oil return mode under the condition that the air conditioning system needs oil return, the requirement on the flow rate of refrigerant returning oil of the indoor units in the high-ratio air conditioning system is met, lubricating oil in the indoor units smoothly returns to the outdoor units, and normal operation of a unit where the air conditioning system is located is ensured. The specific function and processing of the control unit 104 are also referred to as step S140.

In some embodiments, the controlling unit 104, according to the accumulated operation time of the air conditioning system, controls all indoor units of the air conditioning system to return oil according to a set normal oil return mode, including:

the control unit 104 is specifically further configured to determine whether the accumulated operation time of the air conditioning system reaches a first set time (e.g., a first set time T1). 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 control oil return of all indoor units of the air conditioning system according to a set normal oil return mode if it is determined that the accumulated operation time of the air conditioning system has reached a first set time. Of course, if it is determined that the accumulated running time of the air conditioning system does not reach the first set time, continuously controlling all indoor units of the air conditioning system to maintain the current running state. The detailed function and processing of the control unit 104 are also referred to in step S220.

The control unit 104 is specifically configured to, after oil return of all indoor units of the air conditioning system is completed according to a set normal oil return mode, control all indoor units of the air conditioning system to resume to an operation state before oil return, clear an accumulated operation time of the air conditioning system, and then return to obtain the accumulated operation time of the air conditioning system again, and control all indoor units of the air conditioning system to return oil according to the obtained accumulated operation time of the air conditioning system according to the set normal oil return mode when a ratio of the air conditioning system is less than or equal to a set ratio. The oil return of all indoor units of the air conditioning system is completed according to a set normal oil return mode, and the oil return of all indoor units of the air conditioning system is considered to be completed under the condition that the oil return time of all indoor units of the air conditioning system reaches the set normal oil return time according to the set normal oil return mode. The specific function and processing of the control unit 104 are also referred to in step S230.

Specifically, fig. 5 is a schematic flow chart of an embodiment of an oil return control device of a high-ratio air conditioning system. As shown in fig. 5, the oil return control device of the high-ratio air conditioning system according to the present invention includes:

In some embodiments, the control unit 104 controls all indoor units of the air conditioning system to return oil according to a set normal oil return mode, including a normal oil return process in any one of the following cases:

normal oil return process in the first case: the control unit 104 is specifically configured to, if an operation state of an indoor unit before oil return in all indoor units of the air conditioning system is an operation state in the cooling mode, control the operation state of the indoor unit to maintain the operation state of the indoor unit in the cooling mode when the indoor unit is controlled to return oil according to a set normal oil return mode.

Normal oil return process under the second condition: the control unit 104 is further specifically configured to, if an operation state of an indoor unit before oil return in all indoor units of the air conditioning system is an operation state in a heating mode, when controlling the indoor unit to return oil according to a set normal oil return mode, control the operation state of the indoor unit to be converted into an operation state of the indoor unit in a cooling mode.

Normal oil return process under the third condition: the control unit 104 is specifically configured to, if an operation state of an indoor unit in all indoor units of the air conditioning system before oil return is off, control the indoor unit to start up after controlling the indoor unit to return oil according to a set normal oil return mode, and control the operation state of the indoor unit to be an operation state of the indoor unit itself in a cooling mode.

Specifically, as shown in fig. 5, the oil return control device of the high-ratio air conditioning system according to the present invention further includes: in step 3, when the system ratio of the air conditioning system is less than or equal to the set ratio A, controlling all indoor units of the air conditioning system to participate in oil return at the same time, specifically: when the accumulated operation time of the unit where the air conditioning system is located reaches the first set time T1 and the air conditioning system needs oil return, the air conditioning system controls all indoor units to participate in oil return operation according to a normal oil return mode. All indoor units participate in oil return operation according to an oil return mode in the following table.

Current state of indoor unit	Running state of air conditioning system during oil return
		Refrigeration mode	Maintaining current mode operation
Heating mode	Operation in switched cooling mode
		Shutdown	On cooling mode operation

The control unit 104 is further configured to, if it is determined that the ratio of the air conditioning system is greater than a set ratio, group all indoor units of the air conditioning system into more than two groups according to the accumulated running time of the air conditioning system, and control the more than two groups of indoor units of the air conditioning system to return oil according to a set group oil return mode, so that under the condition that the air conditioning system needs oil return, the more than two groups of indoor units of the air conditioning system are controlled to return oil according to the set group oil return mode, the refrigerant flow rate requirement for returning oil to the indoor units in the high-ratio air conditioning system is met, lubricating oil in the indoor units smoothly returns to the outdoor units, and normal operation of the unit where the air conditioning system is located is ensured. The specific function and processing of the control unit 104 are also referred to in step S150.

According to the oil return control device of the high-proportion system, when the proportion of the outdoor unit and the indoor unit of the air conditioning system exceeds a certain proportion, the number of the indoor units participating in oil return is controlled, the requirement of the flow rate of refrigerant returning oil to the indoor unit in the high-proportion air conditioning system is met, lubricating oil in the indoor unit smoothly returns to the outdoor unit, and normal operation of a unit where the air conditioning system is located is guaranteed. Specifically, in an air conditioning system with a high ratio (such as a multi-split air conditioning system), when a unit where the air conditioning system is located performs oil return operation, the indoor units are equally divided into 2 parts according to capacity or number, and each part of the indoor units sequentially participates in oil return to meet the requirement of the flow rate of refrigerant returning to the indoor units, so that lubricating oil in the indoor units smoothly returns to the outdoor units, the normal operation of the air conditioning system is ensured, and damage is avoided.

In some embodiments, the step of controlling the control unit 104 to group all the indoor units of the air conditioning system into two or more groups according to the accumulated running time of the air conditioning system, and to control the two or more groups of indoor units of the air conditioning system to return oil according to a set group oil return mode includes:

the control unit 104 is specifically further configured to determine whether the accumulated operation time of the air conditioning system reaches a second set time (for example, a second set time T2). 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, if it is determined that the accumulated running time of the air conditioning system has reached a second set time, group all the indoor units of the air conditioning system into more than two groups according to the capacity of all the indoor units of the air conditioning system or according to the number of all the indoor units of the air conditioning system, and mark the groups as a first group of indoor units to an nth group of indoor units, where n is a positive integer greater than or equal to 2. Of course, if it is determined that the accumulated running time of the air conditioning system does not reach the second set time, continuously controlling all indoor units of the air conditioning system to maintain the current running state. The specific functions and processes of the control unit 104 are also referred to in step S320.

The control unit 104 is further specifically configured to control a first group of indoor units of all indoor units of the air conditioning system to return oil according to a set group oil return mode, and control a second group of indoor units to an nth group of indoor units of all indoor units of the air conditioning system to stop. The specific functions and processes of the control unit 104 are also referred to in step S330.

The control unit 104 is specifically configured to, when the time for a first group of indoor units in all indoor units of the air conditioning system to return oil according to the set group oil return mode reaches a preset group oil return time, consider that the first group of indoor units in all indoor units of the air conditioning system complete oil return, and control the operation state of the group of indoor units to be the operation state of the group of indoor units in the refrigeration mode after controlling a second group of indoor units in all indoor units of the air conditioning system to be started, so as to control the group of indoor units to return oil. And controlling the indoor unit which does not participate in the oil return to stop. The specific functions and processes of the control unit 104 are also referred to in step S340.

The control unit 104 is specifically configured to, when the oil return time of the second group of indoor units in all indoor units of the air conditioning system reaches a preset group oil return time according to a set group oil return mode, consider that the second group of indoor units in all indoor units of the air conditioning system complete oil return, and control the operation state of the group of indoor units to be the operation state of the group of indoor units in the refrigeration mode after controlling the third group of indoor units in all indoor units of the air conditioning system to be turned on, so as to control the group of indoor units to perform oil return. And controlling the indoor unit which does not participate in the oil return to stop. The specific functions and processes of the control unit 104 are also referred to in step S350.

The control unit 104 is specifically configured to repeat this operation until the nth group of indoor units in all the indoor units of the air conditioning system complete oil return, and then, the control unit controls the operation states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air conditioning system to recover to the operation state before oil return, clears the accumulated operation time of the air conditioning system, and then returns to obtain the accumulated operation time of the air conditioning system again, and when the ratio of the air conditioning system is greater than the set ratio, groups all the indoor units of the air conditioning system again to obtain more than two groups of indoor units according to the obtained accumulated operation time of the air conditioning system again, and controls the more than two groups of indoor units of the air conditioning system to return oil according to the set group oil return mode. The grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air conditioning system last time. The specific function and processing of the control unit 104 are also referred to in step S360.

Specifically, as shown in fig. 5, the oil return control device of the high-ratio air conditioning system according to the present invention further includes: and 4, if the system ratio of the air-conditioning system is greater than the set ratio A, averagely dividing all the indoor units into two groups according to the capacity or the quantity, recording the two groups as a first group of indoor units and a second group of indoor units, and controlling the two groups of indoor units to participate in oil return in sequence. And after the oil return is finished, controlling the air conditioning system to recover the operation mode before the oil return.

Specifically, when the system air-conditioning system has a system air-conditioning ratio greater than the set air-conditioning ratio a, if all the indoor units perform oil return operation, the flow rate of the refrigerant flowing through each indoor unit is slow, and the lubricating oil stored in the indoor units may not be brought back to the outdoor unit, resulting in that the unit in which the air-conditioning system is located cannot operate normally. At the moment, the air conditioning system is in a high-proportion state, a large number of connected indoor units are arranged, copper pipes of the air conditioning system are lengthened, the refrigerant flowing through each indoor unit is reduced, the flow rate is also slowed, and therefore lubricating oil is difficult to bring back to the outdoor unit when oil return runs. If only half of the indoor units are in operation and return oil, the proportion of the air conditioning system is reduced, the refrigerant distribution to each indoor unit is increased, the copper pipe through which the refrigerant flows is shortened, the flow rate is increased, and the lubricating oil can be brought back to the outdoor unit. Therefore, when the accumulated running time of the air conditioning system is larger than the second set time T2, the air conditioning system needs to carry out oil return control, the air conditioning system is divided into two groups according to the capacity or the number of the indoor units, and the ratio of the capacity of each group of indoor units is smaller than the set ratio A. And then, controlling the two groups of indoor units to participate in oil return in sequence. And after the oil return is finished, controlling the air conditioning system to recover the operation mode before the oil return. The second setting time T2 may be the same as the first setting time T1, for example, the same oil return timing determination criterion is set for air conditioning systems of the same manufacturer. Certainly, the second setting time T2 may be different from the second setting time T1, so that the oil return time judgment criteria of the low-ratio air conditioning system and the high-ratio air conditioning system are different for the air conditioning system of the same manufacturer, which is beneficial to more accurately controlling the oil return time of the low-ratio air conditioning system and the oil return time of the high-ratio air conditioning system, and ensures the oil return reliability and the operation reliability of the air conditioning system.

In some embodiments, the controlling unit 104 controls the oil return of the first group of indoor units in all the indoor units of the air conditioning system according to the set group oil return mode, and includes a group oil return process in any one of the following cases:

the grouping oil return process in the first case: the control unit 104 is further specifically configured to, if the operation state of the first group of indoor units in all the indoor units of the air conditioning system before oil return is the operation state in the cooling mode, control the operation state of the group of indoor units to maintain the operation state of the indoor units in the cooling mode when the group of indoor units is controlled to return oil according to the set group oil return mode.

The grouping oil return process in the second case: the control unit 104 is further specifically configured to, if the operation state of the first group of indoor units in all the indoor units of the air conditioning system before oil return is the operation state in the heating mode, when controlling the group of indoor units to return oil according to the set group oil return mode, control the operation state of the group of indoor units to be converted into the operation state of the indoor units in the cooling mode, and control the fans of the group of indoor units to stop.

Grouping oil return process under the third condition: the control unit 104 is further specifically configured to, if the operation state of a first group of indoor units in all the indoor units of the air conditioning system before oil return is a shutdown state, control the throttle device of the air conditioning system to be opened and control the fans of the group of indoor units to be shutdown after the group of indoor units needs to be controlled to be started when the group of indoor units is controlled to return oil according to a set group oil return mode.

Specifically, as shown in fig. 5, the oil return control device of the high-ratio air conditioning system according to the present invention further includes: in step 4, the specific process of controlling the two groups of indoor units to participate in oil return in sequence is as follows:

And under the condition that the first group of indoor units participate in oil return operation, the second group of indoor units are all shut down.

And after oil return is finished, clearing the accumulated running time of the air conditioning system, recalculating new accumulated running time, and regrouping all indoor units when oil return is performed next time. Here, when oil return is performed next time, all indoor units are grouped again, and the result of grouping again needs to be ensured, which is different from the result of grouping in the previous time, so that all indoor units can participate in oil return alternately in the oil return grouping process, and the oil return effect is improved. Therefore, under the high-proportion air-conditioning system, the flow velocity of the refrigerant in the indoor unit during oil return is increased according to the quantity of the indoor units participating in oil return control, so that the flow velocity requirement of the refrigerant returning from the indoor units in the high-proportion air-conditioning system is met, the lubricating oil in the indoor units smoothly returns to the outdoor units, the normal operation of the air-conditioning system is ensured, and the damage is avoided.

Since the processes and functions implemented by the apparatus of this embodiment substantially correspond to the embodiments, principles and examples of the foregoing method, reference may be made to relevant descriptions in the foregoing embodiments for details that are not described in detail in the description of this embodiment, and further description is not provided herein.

By adopting the technical scheme of the invention, through determining the ratio of the air conditioning system, if the ratio of the air conditioning system is less than or equal to the set ratio, more than two groups of indoor units are controlled to participate in oil return simultaneously when the air conditioning system returns oil; if the proportion of the air conditioning system is larger than the set proportion, when the air conditioning system returns oil, all indoor units in the air conditioning system are evenly divided into more than two groups (preferably two groups) according to the capacity or the number, different groups of indoor units in the more than two groups of indoor units are controlled to participate in the oil return in different sequences, the purpose that the more than two groups of indoor units participate in the oil return in different times is achieved, the number of the indoor units participating in the oil return in each time in the more than two groups of indoor units is adjusted, the requirement of the flow rate of refrigerant returning oil of the indoor units in the high proportion air conditioning system is met, lubricating oil in the indoor units smoothly returns to the outdoor units, normal operation of the air conditioning system is guaranteed, damage is avoided, and reliability of the air conditioning system is guaranteed.

According to the embodiment of the invention, the air conditioning system corresponding to the oil return control device of the air conditioning system is also provided. The air conditioning system may include: the oil return control device of the air conditioning system.

Since the processing and functions of the air conditioning system of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing devices, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

By adopting the technical scheme of the invention, through determining the ratio of the air conditioning system, if the ratio of the air conditioning system is less than or equal to the set ratio, more than two groups of indoor units are controlled to participate in oil return simultaneously when the air conditioning system returns oil; if the proportion of the air conditioning system is greater than the set proportion, when the air conditioning system returns oil, all indoor units in the air conditioning system are evenly divided into more than two groups (preferably two groups) according to the capacity or the number, different groups of indoor units in the more than two groups of indoor units are controlled to participate in the oil return in different sequences, the purpose that the more than two groups of indoor units participate in the oil return in different time is achieved, the number of the indoor units participating in the oil return in each time in the more than two groups of indoor units is adjusted, the requirement of the flow rate of refrigerant returning oil of the indoor units in the high proportion air conditioning system is met, lubricating oil in the indoor units smoothly returns to the outdoor units, normal operation of the unit where the air conditioning system is located is guaranteed, and reliable and safe operation of the air conditioning system is guaranteed.

According to an embodiment of the present invention, there is also provided a storage medium corresponding to an oil return control method of an 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 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 foregoing method, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

By adopting the technical scheme of the invention, through determining the ratio of the air conditioning system, if the ratio of the air conditioning system is less than or equal to the set ratio, more than two groups of indoor units are controlled to participate in oil return simultaneously when the air conditioning system returns oil; if the proportion of the air conditioning system is larger than the set proportion, all indoor units in the air conditioning system are evenly divided into more than two groups (preferably two groups) according to the capacity or the quantity when the air conditioning system returns oil, the different groups of indoor units in the more than two groups of indoor units are controlled to participate in oil return in different sequences, the purpose that the more than two groups of indoor units participate in oil return in different times is achieved, the quantity of the indoor units participating in oil return in each time in the more than two groups of indoor units is adjusted, the requirement of the flow rate of refrigerant returning oil of the indoor units in the high proportion air conditioning system is met, lubricating oil in the indoor units smoothly returns to the outdoor units, and the flow rate of the refrigerant when oil return is achieved by controlling the quantity of the indoor units participating in oil return.

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. The oil return control method of the air conditioning system is characterized in that the air conditioning system is provided with an indoor unit and an outdoor unit; the number of the indoor units is more than two, and the number of the outdoor units is more than one; the oil return control method of the air conditioning system comprises the following steps:

acquiring the sum of the capacities of all indoor units of the air conditioning system, and recording the sum as the total capacity of the indoor units of the air conditioning system; acquiring the sum of the capacities of all outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system; acquiring the accumulated running time of the air conditioning system;

determining the ratio of the total capacity of the indoor units of the air-conditioning system to the total capacity of the outdoor units of the air-conditioning system, and recording the ratio as the ratio of the air-conditioning system;

determining whether the ratio of the air conditioning system is less than or equal to a set ratio;

if the proportion of the air-conditioning system is determined to be smaller than or equal to the set proportion, controlling all indoor units of the air-conditioning system to return oil according to the set normal oil return mode according to the accumulated running time of the air-conditioning system;

and if the proportion of the air-conditioning system is determined to be larger than the set proportion, grouping all the indoor units of the air-conditioning system according to the accumulated running time of the air-conditioning system to obtain more than two groups of indoor units, and controlling the more than two groups of indoor units of the air-conditioning system to return oil according to the set grouping oil return mode.

2. The oil return control method of the air conditioning system according to claim 1, wherein controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode according to the accumulated running time of the air conditioning system comprises:

determining whether the accumulated operation time of the air conditioning system reaches a first set time;

if the accumulated operation time of the air conditioning system is determined to reach the first set time, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode;

and after all indoor units of the air conditioning system finish oil return according to a set normal oil return mode, controlling all indoor units of the air conditioning system to recover to the running state running before oil return, clearing the accumulated running time of the air conditioning system, returning to obtain the accumulated running time of the air conditioning system again, and controlling all indoor units of the air conditioning system to return oil according to the set normal oil return mode according to the obtained accumulated running time of the air conditioning system when the ratio of the air conditioning system is less than or equal to the set ratio.

3. The oil return control method of the air conditioning system according to claim 2, wherein controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode comprises:

if the running state of an indoor unit in all the indoor units of the air-conditioning system before oil return is the running state in the refrigeration mode, when the indoor unit is controlled to return oil according to a set normal oil return mode, the running state of the indoor unit needs to be controlled to maintain the running state of the indoor unit in the refrigeration mode;

if the running state of the indoor unit before oil return in all the indoor units of the air conditioning system is the running state in the heating mode, when the indoor unit is controlled to return oil according to a set normal oil return mode, the running state of the indoor unit needs to be controlled to be converted into the running state of the indoor unit in the cooling mode;

if the running state of the indoor units in all the indoor units of the air-conditioning system before oil return is shutdown, when the indoor units are controlled to return oil according to a set normal oil return mode, the indoor units need to be controlled to be started, and then the running state of the indoor units is controlled to be the running state of the indoor units in a refrigeration mode.

4. The oil return control method of the air conditioning system according to any one of claims 1 to 3, wherein the step of grouping all the indoor units of the air conditioning system according to the accumulated running time of the air conditioning system to obtain more than two groups of indoor units and controlling the more than two groups of indoor units of the air conditioning system to return oil according to a set grouping oil return mode comprises the steps of:

determining whether the accumulated running time of the air conditioning system reaches a second set time;

if the accumulated running time of the air conditioning system reaches the second set time, grouping all indoor units of the air conditioning system according to the capacity of all indoor units of the air conditioning system or the quantity of all indoor units of the air conditioning system to obtain more than two groups of indoor units, recording the groups of indoor units as a first group of indoor units to an nth group of indoor units, wherein n is a positive integer greater than or equal to 2;

controlling a first group of indoor units in all indoor units of the air-conditioning system to return oil according to a set grouping oil return mode, and controlling a second group of indoor units to an nth group of indoor units in all indoor units of the air-conditioning system to stop;

under the condition that the oil return time of a first group of indoor units in all indoor units of the air-conditioning system reaches preset grouped oil return time according to a set grouped oil return mode, the first group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a second group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in a refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop;

when the oil return time of a second group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the second group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a third group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop;

by analogy, after the nth group of indoor units in all the indoor units of the air-conditioning system complete oil return, the operation states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are controlled to be restored to the operation state before oil return and reset, and then the operation state is returned to obtain the accumulated operation time of the air-conditioning system again, and under the condition that the ratio of the air-conditioning system is greater than the set ratio, all the indoor units of the air-conditioning system are grouped again to obtain more than two groups of indoor units according to the obtained accumulated operation time of the air-conditioning system again, and the oil return of the more than two groups of indoor units of the air-conditioning system is controlled according to the set grouping oil return mode; the grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air-conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air-conditioning system last time.

5. The oil return control method of the air conditioning system according to claim 4, wherein the step of controlling the oil return of the first group of indoor units in all the indoor units of the air conditioning system according to the set group oil return mode includes:

if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is the running state in the refrigeration mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to maintain the running state of the indoor units in the refrigeration mode;

if the running state of a first group of indoor units in all the indoor units of the air conditioning system before oil return is the running state in the heating mode, when the group of indoor units are controlled to return oil according to the set grouping oil return mode, the running state of the group of indoor units needs to be controlled to be converted into the running state of the indoor units in the cooling mode, and fans of the group of indoor units are controlled to stop;

if the running state of a first group of indoor units in all the indoor units of the air-conditioning system before oil return is a shutdown state, when the group of indoor units are controlled to return oil according to a set grouping oil return mode, the group of indoor units are controlled to be started, a throttling device of the air-conditioning system is controlled to be started, and a fan of the group of indoor units is controlled to be shut down.

6. An oil return control device of an air conditioning system is characterized in that the air conditioning system is provided with an indoor unit and an outdoor unit; the number of the indoor units is more than two, and the number of the outdoor units is more than one; the oil return control device of the air conditioning system comprises:

the acquisition unit is configured to acquire the sum of the capacities of all indoor units of the air conditioning system and record the sum as the total capacity of the indoor units of the air conditioning system; acquiring the sum of the capacities of all outdoor units of the air conditioning system, and recording the sum as the total capacity of the outdoor units of the air conditioning system; acquiring the accumulated running time of the air conditioning system;

the control unit is configured to determine the ratio of the total capacity of indoor units of the air conditioning system to the total capacity of outdoor units of the air conditioning system, and the ratio is recorded as the ratio of the air conditioning system;

the control unit is further configured to determine whether the air conditioning system is smaller than or equal to a set ratio;

the control unit is further configured to control oil return of all indoor units of the air conditioning system according to a set normal oil return mode according to the accumulated running time of the air conditioning system if the proportion of the air conditioning system is determined to be smaller than or equal to a set proportion;

the control unit is further configured to group all indoor units of the air-conditioning system to obtain more than two groups of indoor units according to the accumulated running time of the air-conditioning system if the proportion of the air-conditioning system is determined to be larger than the set proportion, and control the more than two groups of indoor units of the air-conditioning system to return oil according to the set group oil return mode.

7. The oil return control device of an air conditioning system according to claim 6, wherein the control unit controls all indoor units of the air conditioning system to return oil according to a set normal oil return mode according to the accumulated running time of the air conditioning system, and the control unit includes:

determining whether the accumulated running time of the air conditioning system reaches a first set time;

if the accumulated running time of the air conditioning system is determined to reach the first set time, controlling all indoor units of the air conditioning system to return oil according to a set normal oil return mode;

8. The oil return control device of an air conditioning system according to claim 7, wherein the control unit controls oil return of all indoor units of the air conditioning system in a set normal oil return mode, and the control unit includes:

if the running state of the indoor unit before oil return in all the indoor units of the air-conditioning system is the running state in the refrigeration mode, when the indoor unit is controlled to return oil according to the set normal oil return mode, the running state of the indoor unit needs to be controlled to maintain the running state of the indoor unit in the refrigeration mode;

9. The oil return control device of any one of claims 6 to 8, wherein the control unit groups all indoor units of the air conditioning system into two or more groups according to the accumulated running time of the air conditioning system, and controls the two or more groups of indoor units of the air conditioning system to return oil according to a set group oil return mode, and the control unit comprises:

if the accumulated running time of the air conditioning system reaches second set time, grouping all indoor units of the air conditioning system according to the capacity of all indoor units of the air conditioning system or the quantity of all indoor units of the air conditioning system to obtain more than two groups of indoor units, recording the groups as a first group of indoor units to an nth group of indoor units, wherein n is a positive integer greater than or equal to 2;

controlling a first group of indoor units in all indoor units of the air-conditioning system to return oil according to a set group oil return mode, and controlling a second group of indoor units to an nth group of indoor units in all indoor units of the air-conditioning system to stop;

when the oil return time of a first group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the first group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a second group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; and controlling the indoor unit which does not participate in the oil return to stop;

when the oil return time of a second group of indoor units in all indoor units of the air-conditioning system reaches the preset grouped oil return time according to the set grouped oil return mode, the second group of indoor units in all indoor units of the air-conditioning system are considered to finish oil return, and after a third group of indoor units in all indoor units of the air-conditioning system are controlled to be started, the running state of the group of indoor units is controlled to be the running state of the group of indoor units in the refrigeration mode, so that the group of indoor units are controlled to return oil; controlling the indoor units which do not participate in the oil return to stop;

in this analogy, after the nth group of indoor units in all the indoor units of the air-conditioning system complete oil return, the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are considered to complete oil return, the running states of the first group of indoor units to the nth group of indoor units in all the indoor units of the air-conditioning system are controlled to be restored to the running state running before oil return, the accumulated running time of the air-conditioning system is reset, then the running state is returned to obtain the accumulated running time of the air-conditioning system again, and under the condition that the proportion of the air-conditioning system is greater than the set proportion, all the indoor units of the air-conditioning system are grouped again according to the newly obtained accumulated running time of the air-conditioning system to obtain more than two groups of indoor units, and the more than two groups of indoor units of the air-conditioning system are controlled to return oil according to the set grouping oil return mode; the grouping result of more than two groups of indoor units is obtained by grouping all the indoor units of the air conditioning system again, and is different from the grouping result of more than two groups of indoor units obtained by grouping all the indoor units of the air conditioning system last time.

10. The oil return control device of an air conditioning system according to claim 9, wherein the control unit controls oil return of a first group of indoor units among all indoor units of the air conditioning system according to a set group oil return mode, and includes:

11. An air conditioning system, comprising: the oil return control device of an air conditioning system as claimed in any one of claims 6 to 10.

12. A storage medium characterized by comprising a stored program, wherein an apparatus in which the storage medium is located is controlled to execute the oil return control method of an air conditioning system according to any one of claims 1 to 5 when the program is executed.