CN117190556A

CN117190556A - Compressor system, multi-split air conditioner and control method and device for compressor oil return

Info

Publication number: CN117190556A
Application number: CN202210607929.5A
Authority: CN
Inventors: 任善军; 焦华; 王洪伟; 远义忠; 卢大海
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2023-12-08

Abstract

The application relates to the technical field of air conditioning equipment, and discloses a compressor system, which comprises a compressor and an oil separator, wherein the inlet end of the oil separator is connected with the exhaust side of the compressor; further comprises: the oil return flow path comprises a throttling communication assembly and a gas-liquid separator which are sequentially connected through pipelines; the inlet end of the oil return flow path is connected with the oil outlet end of the oil separator; the oil return hole of the gas-liquid separator is connected with the air suction side of the compressor through the outlet end of the oil return flow path; a current detection assembly configured to detect a current value of the compressor; a controller configured to control the throttle communication assembly to communicate or intercept the oil return flow path according to the detection result of the current detection assembly; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided. The application also discloses a multi-split air conditioner, and a control method and a device for compressor oil return.

Description

Compressor system, multi-split air conditioner and control method and device for compressor oil return

Technical Field

The application relates to the technical field of air conditioning equipment, in particular to a compressor system, a multi-split air conditioner and a control method and device for compressor oil return.

Background

At present, the multi-split air conditioner is difficult to return after compressor oil is discharged along with a refrigerant due to longer on-line piping, and the situation that the compressor is damaged due to oil shortage can occur. In order to prevent compressor oil from being discharged out of the compressor along with the refrigerant, an oil separator is arranged in the multi-split air conditioner so as to separate the refrigerant from the compressor oil.

In order to enable the oil separator to return to the compressor, in the prior art, by arranging a capillary tube which is communicated with the bottom of oil content and the low pressure side of the system, the separated oil returns to the air suction side of the compressor under the action of pressure difference between high pressure and low pressure, finally returns to the compressor, and finally returns to a pipeline far away from the compressor, such as an indoor unit, through local circulation.

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

because the efficiency of oil separator is unstable, and the separation of oil and refrigerant need certain velocity of flow to separate, so when the oil is not oily to separate, because the fixed specification of capillary for high low pressure side communicates, the refrigerant can directly by uninstalling to low pressure side, leads to the refrigerant unable to participate in the system circulation, has led to the loss of capacity.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview, and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended as a prelude to the more detailed description that follows.

The embodiment of the disclosure provides a compressor system, a multi-split air conditioner and a control method and device for compressor oil return, so as to avoid the condition of system capacity loss in the oil return process.

In some embodiments, the compressor system includes a compressor and an oil separator, an inlet end of the oil separator being connected to a discharge side of the compressor; further comprises: the oil return flow path comprises a throttling communication assembly and a gas-liquid separator which are sequentially connected through pipelines; the inlet end of the oil return flow path is connected with the oil outlet end of the oil separator; the oil return hole of the gas-liquid separator is connected with the air suction side of the compressor through the outlet end of the oil return flow path; a current detection assembly configured to detect a current value of the compressor; and the controller is configured to control the throttling communication assembly to communicate or cut off the oil return flow path according to the detection result of the current detection assembly.

Optionally, the compressor system further comprises:

the temperature detection assembly is used for detecting a first temperature before the fluid in the oil return flow path passes through the throttling communication assembly and a second temperature after the fluid passes through the throttling communication assembly;

the controller is further configured to control the throttle communication assembly to communicate or intercept the oil return flow path according to a detection result of the current detection assembly and a detection result of the temperature detection assembly.

Optionally, the temperature detection assembly includes: the pre-throttling temperature sensor is arranged between the throttling communication assembly and the compressor; and the temperature sensor after throttling is arranged between the throttling communication assembly and the gas-liquid separator.

Optionally, the oil return flow path further includes: the filter is arranged between the inlet end of the oil return flow path and the throttling communication assembly.

Optionally, the throttle communication assembly includes an electronic expansion valve.

In some embodiments, the multi-split air conditioner includes the compressor system described above.

In some embodiments, the method for controlling oil return of a compressor is applied to the multi-split air conditioner, and includes: under the condition that an oil return flow path is communicated, acquiring a current value of the compressor;

And determining a control strategy for the throttling communication assembly according to the current value interval satisfied by the current value, so that the oil return flow path is kept on or off.

Optionally, if the present current value is greater than a first current threshold, determining a control strategy for the throttle communication assembly includes:

controlling the throttling communication assembly to cut off the oil return flow path;

if the present current value is less than or equal to the first current threshold value, determining a control strategy for the throttled communication assembly, comprising:

acquiring a first temperature before the fluid in the oil return flow path passes through the throttling communication assembly and a second temperature after the fluid passes through the throttling communication assembly;

a control strategy for the throttle communication assembly is determined based on a current temperature difference of the first temperature and the second temperature.

Optionally, the obtaining of the first current threshold includes:

acquiring a corresponding relation among the frequency of the compressor, the oil state in the compressor and the current of the compressor;

acquiring the current frequency of the compressor, and determining the corresponding compressor current in the compressor in a full oil state as a first preset current under the current frequency;

Determining the first current threshold according to the first preset current; the first preset current is greater than the first current threshold.

Optionally, the determining a control strategy for the throttle communication assembly according to the current temperature difference between the first temperature and the second temperature includes:

if the current temperature difference is greater than the first temperature difference, a control strategy for the throttle communication assembly includes:

closing the throttling communication assembly under the current opening degree to cut off the oil return flow path;

if the current temperature difference is less than or equal to a second temperature difference, a control strategy for the throttle communication assembly includes:

the opening degree of the throttling communication assembly is increased, so that the oil return flow path is kept communicated, and the oil return quantity is increased;

wherein the first temperature difference is greater than the second temperature difference.

Optionally, the increasing the opening degree of the throttle communication assembly includes:

determining an opening degree adjusting value for improving the opening degree of the throttling communication assembly according to the current value;

and determining the sum of the current opening and the opening adjusting value as a target opening, and controlling the throttling communication assembly to be improved to the target opening according to a set speed.

Optionally, the determining an opening degree adjustment value for increasing the opening degree of the throttle communication assembly according to the current value includes:

if the current value is larger than a second current threshold value, determining the opening adjustment value as a first opening adjustment value;

if the current value is smaller than or equal to a second current threshold value, determining the opening adjustment value as a second opening adjustment value;

wherein the second current threshold is less than the first current threshold; the first opening adjustment value is greater than the second opening adjustment value.

Optionally, the obtaining of the second current threshold includes:

acquiring the current frequency of the compressor, and determining the corresponding compressor current in the compressor in a non-full oil state as a second preset current under the current frequency;

determining the second current threshold according to the second preset current; the second preset current is greater than the second current threshold;

wherein the non-full oil state includes an oil-starved state and an oil-present state; the second preset current is greater than the first preset current.

Optionally, the above oil return control method with a compressor further includes:

Determining interval duration for controlling the communication of the oil return flow path according to the operation frequency of the compressor; the operating frequency of the compressor is inversely related to the interval duration.

In some embodiments, the control device for compressor oil return is applied to the multi-split air conditioner and comprises a processor and a memory storing program instructions, wherein the processor is configured to execute the control method for compressor oil return when the program instructions are executed.

The compressor system, the multi-split air conditioner and the control method and the device for compressor oil return provided by the embodiment of the disclosure can realize the following technical effects:

the oil state of the compressor is determined by detecting the current value of the compressor so as to control a throttling communication assembly arranged on the oil return flow path, and throttling conduction or cutoff of the oil return flow path is realized. Therefore, under the throttling conduction state of the oil return flow path, the compressor oil can return to the air suction side of the compressor through the oil return hole of the gas-liquid separator, and the abrasion of the compressor caused by the oil shortage state in the compressor is avoided; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided.

The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the application.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which like reference numerals refer to similar elements, and in which:

FIG. 1 is a schematic view of a connection structure of a related art compressor system;

FIG. 2a is a schematic diagram illustrating the connection of a compressor system provided by an embodiment of the present disclosure;

FIG. 2b is a schematic diagram of a controller connection for the compressor system of FIG. 2 a;

FIG. 3a is a schematic diagram illustrating the connection of another compressor system provided by an embodiment of the present disclosure;

FIG. 3b is a schematic diagram of a controller connection of the compressor system of FIG. 3 a;

fig. 4a is a schematic connection diagram of a multi-split air conditioner according to an embodiment of the present disclosure;

FIG. 4b is a schematic diagram illustrating the connection of the controller of the multi-split air conditioner of FIG. 4 a;

FIG. 5 is a flow chart of a control method for compressor oil return provided by an embodiment of the present disclosure;

FIG. 6 is a flow chart of another control method for compressor oil return provided by an embodiment of the present disclosure;

FIG. 7 is a flow chart of another control method for compressor oil return provided by an embodiment of the present disclosure;

fig. 8 is a schematic diagram of a control device for compressor oil return according to an embodiment of the present disclosure.

Detailed Description

So that the manner in which the features and techniques of the disclosed embodiments can be understood in more detail, a more particular description of the embodiments of the disclosure, briefly summarized below, may be had by reference to the appended drawings, which are not intended to be limiting of the embodiments of the disclosure. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may still be practiced without these details. In other instances, well-known structures and devices may be shown simplified in order to simplify the drawing.

The terms first, second and the like in the description and in the claims of the embodiments of the disclosure and in the above-described figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe embodiments of the present disclosure. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

The term "plurality" means two or more, unless otherwise indicated.

In the embodiment of the present disclosure, the character "/" indicates that the front and rear objects are an or relationship. For example, A/B represents: a or B.

The term "and/or" is an associative relationship that describes an object, meaning that there may be three relationships. For example, a and/or B, represent: a or B, or, A and B.

The term "corresponding" may refer to an association or binding relationship, and the correspondence between a and B refers to an association or binding relationship between a and B.

Fig. 1 is a schematic view of a connection structure of a related art compressor system.

As shown in fig. 1, the oil return flow path of the compressor system is formed by sequentially connecting a compressor 110, an oil separator 120, a capillary tube 130 and a gas-liquid separator 140; the oil outlet end of the oil separator 120 is connected to the inlet end of the capillary tube 130; the refrigerant outlet of the oil separator 120 is connected to the refrigeration cycle.

Here, the oil bottom is communicated with the inlet end (low pressure side) of the gas-liquid separator by a capillary tube, and the separated compressor oil returns to the suction side of the compressor under the action of the pressure difference between high pressure and low pressure, directly returns to the compressor for local circulation, and does not enter the pipeline of the internal machine and the like far away from the compressor.

Because the specifications of the capillary tubes installed in the system cannot be changed, all working conditions cannot be considered; meanwhile, as a certain flow rate is needed for separating the compressor oil and the refrigerant, when the compressor runs at a low frequency, the efficiency of the oil separator is relatively low, and as the oil and the refrigerant can be separated at a certain flow rate, the oil is separated without oil, and at the moment, because of the fixed specification of the capillary tube, the refrigerant can be directly unloaded to the low pressure side, so that the refrigerant cannot participate in the system circulation, and the capacity loss is caused.

Therefore, the scheme provides a novel compressor system, so that the oil return process is improved through structural improvement and a control strategy.

Fig. 2a is a schematic connection diagram of a compressor system according to an embodiment of the present disclosure, and fig. 2b is a schematic connection diagram of a controller of the compressor system.

Referring to fig. 2a and 2b, a compressor system according to an embodiment of the present disclosure includes a compressor 200 and an oil separator 210, wherein an inlet end of the oil separator 210 is connected to an exhaust side of the compressor 200; further comprises:

the oil return flow path comprises a throttling communication assembly 220 and a gas-liquid separator 230 which are sequentially connected through pipelines; the inlet end of the oil return flow path is connected with the oil outlet end of the oil separator 210; the oil return hole of the gas-liquid separator 230 is connected to the suction side of the compressor 200 through the outlet end of the oil return flow path;

A current detection component 240 configured to detect a current value of the compressor 200;

and a controller 250 configured to control the throttle communication assembly 240 to communicate or shut off the return oil flow path according to the detection result of the current detection assembly 240.

Generally, a multi-split air conditioner includes one or more outdoor units and a plurality of indoor units. The compressor system is disposed in the outdoor unit. In this embodiment, a compressor system in a multi-split air conditioner is taken as an example, and a description will be given of a scheme. In other embodiments, the multi-split air conditioner may include one or more of the compressor systems of the present embodiments.

Here, through feeding back the oil return flow path to the suction side of the compressor through the gas-liquid separator for the compressor oil can get back to the compressor through the oil return hole of the gas-liquid separator again, can avoid the condition that the oil that the compressor oil directly returns to the compressor suction side probably leads to directly gets into the compressor vortex dish, thereby avoid because the compressor oil can't be compressed, the broken condition of vortex dish that leads to takes place.

According to the compressor system provided by the embodiment of the disclosure, the current detection device is arranged to detect the current value of the compressor and determine the oil state of the compressor so as to control the throttling communication assembly arranged on the oil return flow path, and throttling conduction or cutoff of the oil return flow path is realized. Therefore, under the throttling conduction state of the oil return flow path, the compressor oil can return to the air suction side of the compressor through the oil return hole of the gas-liquid separator, and the abrasion of the compressor caused by the oil shortage state in the compressor is avoided; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided.

Optionally, the oil return flow path further includes: the filter 260 is disposed between the inlet end of the return flow path and the throttle communication assembly 220. To avoid clogging of the throttle communication assembly 220 by fluid impurities in the return flow path.

Optionally, the throttle communication assembly 220 includes an electronic expansion valve. The electronic expansion valve can be used for adjusting the opening according to the instruction and has a throttling function. Here, when the electronic expansion valve is closed, the oil return flow path is blocked, and the oil return operation is stopped. When the electronic expansion valve is opened, the oil return flow path is communicated, and the fluid in the flow path is throttled; and the oil return amount can be adjusted by adjusting the opening of the electromagnetic valve. In some embodiments, a solenoid valve and capillary tube arranged in series may also be used as the throttling communication assembly described above. When the electromagnetic valve is closed, the oil return flow path is cut off; when the solenoid valve is opened, the return flow path is opened, and the capillary tube throttles the fluid in the flow path.

Fig. 3a is a schematic connection diagram of another compressor system provided in an embodiment of the present disclosure, and fig. 3b is a schematic connection diagram of a controller of the compressor system.

As shown in conjunction with fig. 3a and 3b, the compressor system provided in the embodiment of the present disclosure includes a compressor 300 and an oil separator 310, wherein an inlet end of the oil separator 310 is connected to an exhaust side of the compressor 300; further comprises:

The oil return flow path comprises a throttling communication assembly 320 and a gas-liquid separator 330 which are sequentially connected through pipelines; the inlet end of the oil return flow path is connected with the oil outlet end of the oil separator 310; the oil return hole of the gas-liquid separator 330 is connected to the suction side of the compressor 300 through the outlet end of the oil return flow path;

a current detection assembly 340 configured to detect a current value of the compressor 300;

a temperature detecting component 350, configured to detect a first temperature of the fluid in the oil return flow path before the fluid passes through the throttle communication component 320 and a second temperature of the fluid after the fluid passes through the throttle communication component 320;

and a controller 360 configured to control the throttle communication assembly 320 to communicate or shut off the return oil flow path according to the detection result of the current detection assembly 340 and the detection result of the temperature detection assembly 350.

Here, the temperature detection assembly is used for detecting the pre-throttling temperature and the post-throttling temperature of the throttling communication assembly; because the compressor oil has no obvious gas-liquid phase change, the temperature can not obviously change when the compressor oil passes through the throttling communication assembly; and the temperature of the refrigerant is obviously reduced after throttling. Therefore, the oil state of the compressor can be determined through the detection results of the temperature detection assembly and the current detection assembly so as to control the throttling communication assembly arranged on the oil return flow path, and throttling conduction or cutoff of the oil return flow path is realized.

Optionally, the temperature detection assembly 350 includes: a pre-throttle temperature sensor 351 disposed between the throttle communication assembly 320 and the compressor 300; the post-throttling temperature sensor 352 is disposed between the throttling communication assembly 320 and the gas-liquid separator 330. The temperature change condition of the fluid before and after throttling is obtained through a temperature sensor. Here, the pre-throttle temperature sensor 351 may be a compressor top temperature sensor or a temperature sensor provided between the compressor discharge side and the throttle communication device.

Optionally, the oil return flow path further includes: the filter 370 is disposed between the inlet end of the return flow path and the throttle communication assembly 320. To avoid clogging of the throttle communication assembly 320 by fluid impurities in the return flow path.

Optionally, the throttle communication assembly 320 includes an electronic expansion valve. The electronic expansion valve can be used for adjusting the opening according to the instruction and has a throttling function. Here, when the electronic expansion valve is closed, the oil return flow path is blocked, and the oil return operation is stopped. When the electronic expansion valve is opened, the oil return flow path is communicated, and the fluid in the flow path is throttled; and the oil return amount can be adjusted by adjusting the opening of the electromagnetic valve.

Therefore, the throttle communication assembly can be controlled to communicate or cut off the oil return flow path according to the detection result of the current detection assembly and the detection result of the temperature detection assembly; under the throttle conduction state of the oil return flow path, the compressor oil can return to the air suction side of the compressor through the oil return hole of the gas-liquid separator, and the abrasion of the compressor caused by the oil shortage state in the compressor is avoided; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided.

Fig. 4a shows a connection schematic diagram of a multi-split air conditioner, and fig. 4b shows a connection schematic diagram of a controller of the multi-split air conditioner.

As shown in fig. 4a and 4b, the multi-split air conditioner includes a compressor 400, a main flow path, and an oil return flow path. The multi-split air conditioner includes one or more outdoor units (corresponding to one or more outdoor heat exchangers) and a plurality of indoor units (corresponding to one or more indoor heat exchangers). In this embodiment, an example of a refrigerant circulation line in which one outdoor heat exchanger and one indoor heat exchanger in a multi-split air conditioner are located will be described. The technical scheme provided by the embodiment can be provided by a person skilled in the art to realize the connection of the indoor unit and the outdoor unit of the multi-split air conditioner, so that a complete refrigerant circulation loop of the multi-split air conditioner is formed. In other embodiments, the multi-split air conditioner may include one or more refrigerant circulation pipes configured by the compressor, the main flow path, and the oil return flow path in this embodiment.

The main flow path includes a compressor 400, an oil separator 410, a four-way valve 421, an outdoor heat exchanger 422, a main line throttle 423, and an indoor heat exchanger 424, which are sequentially connected through a main line.

The oil return flow path comprises a throttling communication assembly 430 and a gas-liquid separator 440 which are sequentially connected through pipelines; an inlet end of the oil return flow path is connected to an oil outlet end of the oil separator 410; the oil return hole of the gas-liquid separator 440 is connected to the suction side of the compressor 400 through the outlet end of the oil return flow path.

Taking the refrigeration mode as an example, after the refrigerant and the compressor oil output from the compressor 400 enter the oil separator 410, the refrigerant is output through the refrigerant outlet of the oil separator 410, enters the indoor side after entering the outdoor heat exchanger 422 through the four-way valve 421, is throttled by the main pipeline throttling device 423 to become a low-temperature low-pressure refrigerant, performs evaporation heat exchange in the indoor heat exchanger 424, performs heat exchange with indoor air, sends cool air into the indoor, and then enters the gas-liquid separator 440 through the four-way valve 421 and returns to the suction side of the compressor 400.

After the refrigerant and the compressor oil output from the compressor 400 enter the oil separator 410, the compressor oil is output from the oil outlet end of the oil separator 410, enters the gas-liquid separator 440 after passing through the throttle communication assembly 430, and returns to the suction side of the compressor 400 through the oil return hole of the gas-liquid separator 440.

Further, the multi-split air conditioner further includes a current detection assembly 450 and a controller 460. The current detection assembly 450 is disposed in the compressor electric cabinet and configured to detect a current value of the compressor 400, thereby judging whether the compressor is starved according to a current change of the compressor 400. The controller 460 is configured to control the throttle communication assembly 430 to communicate or shut off the return oil flow path according to the detection result of the current detection assembly 450.

Further, the throttle communication assembly 430 includes an electronic expansion valve. When the electronic expansion valve is closed, the oil return flow path is cut off, and the oil return action is stopped. When the electronic expansion valve is opened, the oil return flow path is communicated, and the fluid in the flow path is throttled; and the oil return amount can be adjusted by adjusting the opening of the electromagnetic valve.

Further, the multi-split air conditioner further includes a temperature detecting component 470, configured to detect a first temperature of the fluid in the oil return flow path before the fluid passes through the throttling communication component 430 and a second temperature after the fluid passes through the throttling communication component 430; the controller 460 is configured to control the throttle communication assembly to communicate or shut off the oil return flow path based on the detection result of the current detection assembly and the detection result of the temperature detection assembly.

Specifically, the temperature sensing assembly 470 includes a pre-throttle temperature sensor 471 disposed between the throttle communication assembly 430 and the compressor 400 and a post-throttle temperature sensor 472 disposed between the throttle communication assembly 430 and the gas-liquid separator 440.

Further, a filter 480 is provided between the inlet end of the return flow path and the throttle communication assembly 430. To avoid clogging of the throttle communication assembly 4300 by fluid impurities in the return flow path.

Fig. 5 is a flow chart of a control method for compressor oil return, which is provided by the embodiment of the disclosure, and is applied to the multi-split air conditioner shown in fig. 4. The method can be executed by a processor of the multi-split air conditioner, and can also be executed in a cloud server communicated with the multi-split air conditioner; the method can also be executed at the control end of the multi-split air conditioner. In the embodiment of the disclosure, a processor of the multi-split air conditioner is taken as an execution main body, and a description is given of a scheme.

As shown in fig. 5, the control method for compressor oil return includes:

in step S501, when the oil return flow path is in communication, a current value of the compressor is obtained.

Here, the oil return flow path is opened by the throttle communication assembly, and the oil outlet end of the oil separator is communicated with the pipeline on the suction side of the compressor. The current value of the compressor is obtained through a current detection assembly, wherein the current detection assembly can comprise a current detection circuit or a detection device such as a universal meter.

Step S502, determining a control strategy for throttling the communicating component according to a current value interval satisfied by the current value, so that the oil return flow path is kept connected or disconnected.

The oil states corresponding to the different current values of the compressor are different, so that the corresponding compressor oil state is obtained through the current value interval satisfied by the current value, and accordingly, the corresponding throttle communication assembly control strategy is determined to adjust the connection or disconnection of the oil return flow path. Therefore, under the throttling conduction state of the oil return flow path, the compressor oil can return to the air suction side of the compressor through the oil return hole of the gas-liquid separator, and the abrasion of the compressor caused by the oil shortage state in the compressor is avoided; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided.

Fig. 6 is a flow chart of a control method for compressor oil return, which is provided by an embodiment of the present disclosure, and is applied to the multi-split air conditioner shown in fig. 4. In the embodiment of the disclosure, a processor of the multi-split air conditioner is taken as an execution main body, and a description is given of a scheme.

As shown in fig. 6, the control method for compressor oil return includes:

in step S601, when the oil return flow path is connected, a current value of the compressor is obtained.

In step S602, if the present current value is greater than the first current threshold value, the throttle communication assembly is controlled to cut off the oil return flow path.

In step S603, if the current value is less than or equal to the first current threshold, a first temperature of the fluid in the oil return flow path before passing through the throttling communication assembly and a second temperature after passing through the throttling communication assembly are obtained.

Step S604, determining a control strategy for throttling the communication component according to the current temperature difference between the first temperature and the second temperature.

Here, the first current threshold value is used to represent a compressor current value when the oil state of the compressor is the full oil state. If the current value is larger than the first current threshold value, the current compressor oil return state is normal, the oil return flow path can be cut off, and after the compressor oil in the compressor consumes/flows out a part, the conduction of the oil return flow path is restored. If the current value is smaller than or equal to the first current threshold value, the current oil state of the compressor is not full, and whether oil can return or not needs to be determined according to temperature changes before and after throttling in an oil return pipeline, so that unnecessary oil return actions are avoided.

Optionally, the obtaining of the first current threshold includes: acquiring a corresponding relation among the frequency of the compressor, the oil state in the compressor and the current of the compressor; acquiring the current frequency of a compressor, and determining the corresponding compressor current in the compressor in a full oil state as a first preset current under the current frequency; determining a first current threshold according to a first preset current; the first preset current is greater than a first current threshold.

Here, the currents corresponding to different frequency values of the compressor in the same oil state may be obtained through a test method, thereby obtaining the above-described correspondence. For example, the current corresponding to the different frequency values of the compressor in the full oil state is obtained, so that the corresponding relation among the frequency of the compressor, the full oil state and the current of the compressor is obtained. When the current compressor frequency is obtained, the current value of the compressor in the full oil state corresponding to the current compressor frequency can be obtained through inquiring a database and used as a first preset current, so that the first current threshold value is determined according to the first preset current.

In this embodiment, the first current threshold is obtained by:

I _n1 ＝k ₁ ×I _m1

wherein I is _n1 For a first current threshold, I _m1 For a first preset current, k ₁ As a result of the first weight value,k ₁ ＜1。

in some embodiments, k is determined from the current frequency of the compressor ₁ Is the value of (1), the frequency of the compressor and k ₁ Is positively correlated with the value of (c). Further, k ₁ The value of (2) is in the range of 0.85-0.99, for example, 0.85, 0.88, 0.90, 0.93, 0.95, 0.99, etc. In the present embodiment k ₁ ＝0.9。

Optionally, determining a control strategy for throttling the communication assembly according to a current temperature difference between the first temperature and the second temperature includes:

If the current temperature difference is greater than the first temperature difference, a control strategy for throttling the communication assembly includes:

closing the throttling communication assembly under the current opening to cut off the oil return flow path;

if the current temperature difference is less than or equal to the second temperature difference, a control strategy for throttling the communication assembly includes:

Here, it is determined whether a majority of the fluid in the pipeline is a refrigerant or a compressor oil by a current temperature difference between the first temperature and the second temperature. Because the compressor oil has no obvious gas-liquid phase change, when all or most of the fluid passing through the oil return flow path is the compressor oil, the temperature of the fluid before and after throttling does not change obviously; and the temperature of the refrigerant is obviously reduced after throttling. The temperature sensing assembly may thus be used to determine the composition of the fluid within the return flow path to implement a corresponding control strategy.

The first temperature difference is used to indicate that the temperature of the fluid in the pipeline is greatly changed before and after throttling. When the current temperature difference is larger than the first temperature difference, the fact that all or most of fluid in the pipeline is refrigerant is indicated, and oil in the oil separator can be recovered. At this time, if the throttle communication assembly is continuously opened, the oil return flow path is communicated, and because the exhaust and the suction of the compressor are pressure relief, the overall pressure difference of the system is unfavorable, the oil remained in the system pipeline cannot return under the action of the high-flow-rate refrigerant, and the oil return of the system is unfavorable, so that the throttle communication assembly is required to be closed, and the oil return flow path is cut off.

The second temperature difference is used to indicate that the temperature of the fluid in the pipeline has less variation before and after throttling. When the current temperature difference is smaller than or equal to the second temperature difference, the fact that all or most of fluid in the pipeline is compressor oil is indicated, a large amount of compressor oil is still left in the oil separator, oil return is not completed, at the moment, the opening degree of the throttling communication device can be increased on the current basis, the oil return quantity is increased, and the oil return rate is accelerated.

Alternatively, the value of the first temperature difference is greater than or equal to 5 ℃, and the value range of the first temperature difference may be set to [5 ℃,7 ℃ ], for example, 5 ℃, 6 ℃,7 ℃; the first temperature difference was set to 5 ℃ in this example. The value of the second temperature difference is less than or equal to 2 ℃, and the value range of the second temperature difference may be set to (0 ℃,2 ℃) such as 1.2 ℃, 1.5 ℃, 1.7 ℃,2 ℃, and in this embodiment, the second temperature difference is set to 2 ℃.

Further, increasing the opening of the throttle communication assembly includes:

and determining the sum of the current opening and the opening adjustment value as a target opening, and controlling the throttling communication assembly to be increased to the target opening according to the set speed for adjustment.

Here, the opening degree of the throttle communication assembly is increased so that the oil return amount can be increased, and the current value can represent the oil state of the compressor. Therefore, the opening degree of the throttling communication assembly is determined through the current value, and the oil return rate of the oil return flow path is adjusted according to the oil state of the compressor.

The corresponding relation between the compressor current value and the opening degree adjusting value can be obtained through a test method; after the current value is obtained, the opening adjustment value corresponding to the current value can be obtained by inquiring a database, so that the target opening is determined according to the opening adjustment value.

Further, determining an opening degree adjustment value for increasing the opening degree of the throttle communication assembly according to the current value may include:

obtaining a current difference value between the current value and a first preset current;

and determining an opening degree adjusting value for improving the opening degree of the throttling communication assembly according to the absolute value of the current difference value between the current value and the first preset current.

Here, the absolute value of the current difference and the absolute value of the difference of the first preset current are inversely related to the magnitude of the opening degree adjustment value.

The corresponding relation between the compressor current difference value and the opening degree adjusting value can be obtained through a test method; after the current value is obtained, the current difference value between the current value and the first preset current in the oil-full state can be obtained by inquiring a database, so that the opening adjustment value corresponding to the current difference value is obtained according to the corresponding relation, and the target opening is determined according to the opening adjustment value.

Or, the correspondence between the compressor current value and the opening adjustment value may be in the form of a formula, and after the current compressor current value is obtained, the opening adjustment value corresponding to the current value may be calculated by using the difference between the current value and the first preset current in the oil-full state to assign a value to an independent variable of the formula.

Further, determining an opening degree adjustment value for increasing the opening degree of the throttle assembly according to the current value includes:

if the current value is larger than the second current threshold value, determining the opening adjustment value as a first opening adjustment value;

if the current value is smaller than or equal to the second current threshold value, determining the opening adjustment value as a second opening adjustment value;

Here, the second current threshold is used to represent a current threshold at which the compressor is not full of oil, so that it is possible to determine the opening adjustment value according to the oil state of the compressor, thereby adjusting the oil return rate of the oil return flow path.

Obtaining a second current threshold, comprising:

determining a second current threshold according to a second preset current; the second preset current is greater than a second current threshold;

Here, the currents corresponding to different frequency values of the compressor in the same oil state may be obtained through a test method, thereby obtaining the above-described correspondence. For example, the current corresponding to the different frequency values of the compressor in the non-full oil state is obtained, so that the corresponding relation among the frequency of the compressor, the non-full oil state and the current of the compressor is obtained. When the current compressor frequency is obtained, the current value of the compressor in the non-full oil state corresponding to the current compressor frequency can be obtained through inquiring a database and used as a second preset current, so that the second current threshold value is determined according to the second preset current. Specifically, the compressor current value in the oil state corresponding to the current compressor frequency may be used as the second preset current.

In this embodiment, the second current threshold is obtained by:

I _n2 ＝k ₂ ×I _m2

wherein I is _n2 For the second current threshold, I _m2 For a second preset current, k ₂ As weighted value, k ₂ ＜1。

In some embodiments, k is determined from the current frequency of the compressor ₂ Is the value of (1), the frequency of the compressor and k ₂ Is positively correlated with the value of (c). Further, k ₂ The value of (2) is in the range of 0.85-0.99, for example, 0.85, 0.88, 0.90, 0.93, 0.95, 0.99, etc. In the present embodiment k ₂ ＝0.9。

In this way, according to the control method for the oil return of the compressor of the multi-split air conditioner, the oil state of the compressor is determined by detecting the current value of the compressor so as to control the throttling communication assembly arranged on the oil return flow path, and throttling conduction or cutoff of the oil return flow path is achieved. And when the current value of the compressor indicates that the oil state of the compressor is not full oil state, the connection or disconnection of the oil return flow path is determined through the temperature difference value before and after throttling of the fluid in the oil return flow path. Under the throttle conduction state of the oil return flow path, the compressor oil can return to the air suction side of the compressor through the oil return hole of the gas-liquid separator, and the abrasion of the compressor caused by the oil shortage state in the compressor is avoided; under the condition that the oil return flow path is blocked, unnecessary oil return action can be avoided, and system capacity loss caused by communication between the high pressure side and the low pressure side is avoided.

Fig. 7 is a flow chart of a control method for compressor oil return, which is provided by the embodiment of the disclosure, and is applied to the multi-split air conditioner shown in fig. 4. In the embodiment of the disclosure, a processor of the multi-split air conditioner is taken as an execution main body, and a description is given of a scheme.

As shown in fig. 7, the control method for compressor oil return includes:

step S701, obtaining the operation frequency of the compressor under the condition that the operation state of the multi-split air conditioner is stable.

Step S702, determining interval duration for controlling the communication of an oil return flow path according to the operation frequency of the compressor; the operating frequency of the compressor is inversely related to the interval duration.

In step S703, when the oil return flow path is connected, the current value of the compressor is obtained.

Step S704, if the current value is larger than the first current threshold corresponding to the oil full state, the throttle communication assembly is controlled to cut off the oil return flow path. And after the oil return flow path is cut off, if the interval duration is not reached and the current value is within the set current interval, controlling the oil return flow path to be communicated.

In step S705, if the current value is less than or equal to the first current threshold, a temperature difference Δt between the first temperature T1 of the fluid in the oil return flow path before passing through the throttle communication assembly and the second temperature T2 after passing through the throttle communication assembly is obtained.

Step S706, if DeltaT is greater than the first temperature difference T _S1 And closing the throttling communication assembly under the current opening degree to cut off the oil return flow path.

Step S707, if DeltaT is smaller than or equal to the first temperature difference TS1 and larger than the second temperature difference TS2, controlling the throttle communication assembly to keep the current opening in the interval time so as to communicate the oil return flow path;

in step S708, if Δt is smaller than the second temperature difference TS2, the opening of the throttle communication assembly is increased during the interval period, so that the oil return flow path is kept in communication, and the oil return amount is increased.

The method for obtaining the stable running state of the multi-split air conditioner comprises the following steps:

detecting the high pressure of an exhaust port of the compressor and the low pressure of an air suction port of the compressor, and determining the ratio of the high pressure to the low pressure as a compression ratio;

and under the condition that the compression ratio is within a preset range, the running state of the multi-split air conditioner is considered to be stable.

The set current interval is used for indicating that the oil state of the compressor is in an oil state which is not full of oil and is not short of oil.

In general, since the compressor is in an oil-starved state, wear may increase and a current value may rise. Thus, corresponds to a current threshold I representing a full oil condition of the compressor ₁ The current threshold in the oil state is denoted as I ₂ The current threshold in the oil-starved condition is denoted as I ₃ I1 < I ₂ ＜I ₃ . The set current interval is represented as [0.9I ] ₂ ,1.1I ₂ ]Current threshold I representing the current value and the oil state ₂ The deviation of (2) is within 10%.

Fig. 8 is a schematic diagram of a control device for compressor oil return, which is provided in an embodiment of the present application and is applied to the multi-split air conditioner shown in fig. 4. As shown in fig. 8, the control device for compressor oil return includes:

A processor (processor) 80 and a memory (memory) 81. Optionally, the apparatus may further comprise a communication interface (Communication Interface) 82 and a bus 83. The processor 80, the communication interface 82, and the memory 81 may communicate with each other via the bus 83. The communication interface 82 may be used for information transfer. The processor 80 may call logic instructions in the memory 81 to perform the control method for compressor oil return of the above-described embodiment.

Further, the logic instructions in the memory 81 described above may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand alone product.

The memory 81 is a computer readable storage medium that can be used to store a software program, a computer executable program, such as program instructions/modules corresponding to the methods in the embodiments of the present disclosure. The processor 80 executes functional applications and data processing by running program instructions/modules stored in the memory 81, i.e., implements the control method for compressor oil return in the above-described embodiment.

The memory 81 may include a storage program area that may store an operating system, at least one application program required for functions, and a storage data area; the storage data area may store data created according to the use of the terminal device, etc. In addition, the memory 81 may include a high-speed random access memory, and may also include a nonvolatile memory.

The embodiment of the disclosure provides a multi-split air conditioner, which comprises the control method for compressor oil return.

Embodiments of the present disclosure provide a computer-readable storage medium storing computer-executable instructions configured to perform the above-described control method for compressor oil return.

The disclosed embodiments provide a computer program product comprising a computer program stored on a computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, cause the computer to perform the above-described control method for compressor oil return.

The computer readable storage medium may be a transitory computer readable storage medium or a non-transitory computer readable storage medium.

Embodiments of the present disclosure may be embodied in a software product stored on a storage medium, including one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of a method according to embodiments of the present disclosure. And the aforementioned storage medium may be a non-transitory storage medium including: a plurality of media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or a transitory storage medium.

The above description and the drawings illustrate embodiments of the disclosure sufficiently to enable those skilled in the art to practice them. Other embodiments may involve structural, logical, electrical, process, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of others. Moreover, the terminology used in the present application is for the purpose of describing embodiments only and is not intended to limit the claims. As used in the description of the embodiments and the claims, the singular forms "a," "an," and "the" (the) are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, the term "and/or" as used in this disclosure is meant to encompass any and all possible combinations of one or more of the associated listed. Furthermore, when used in the present disclosure, the terms "comprises," "comprising," and/or variations thereof, mean that the recited features, integers, steps, operations, elements, and/or components are present, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Without further limitation, an element defined by the phrase "comprising one …" does not exclude the presence of other like elements in a process, method or apparatus comprising such elements. In this context, each embodiment may be described with emphasis on the differences from the other embodiments, and the same similar parts between the various embodiments may be referred to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method sections disclosed in the embodiments, the description of the method sections may be referred to for relevance.

Those of skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. The skilled artisan may use different methods for each particular application to achieve the described functionality, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. It will be clearly understood by those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

In the embodiments disclosed herein, the disclosed methods, articles of manufacture (including but not limited to devices, apparatuses, etc.) may be practiced in other ways. For example, the apparatus embodiments described above are merely illustrative, and for example, the division of the units may be merely a logical function division, and there may be additional divisions when actually implemented, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. In addition, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form. The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to implement the present embodiment. In addition, each functional unit in the embodiments of the present disclosure may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. In the description corresponding to the flowcharts and block diagrams in the figures, operations or steps corresponding to different blocks may also occur in different orders than that disclosed in the description, and sometimes no specific order exists between different operations or steps. For example, two consecutive operations or steps may actually be performed substantially in parallel, they may sometimes be performed in reverse order, which may be dependent on the functions involved. Each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Claims

1. A compressor system comprising a compressor and an oil separator, an inlet end of the oil separator being connected to an exhaust side of the compressor; characterized by further comprising:

the oil return flow path comprises a throttling communication assembly and a gas-liquid separator which are sequentially connected through pipelines; the inlet end of the oil return flow path is connected with the oil outlet end of the oil separator; the oil return hole of the gas-liquid separator is connected with the air suction side of the compressor through the outlet end of the oil return flow path;

a current detection assembly configured to detect a current value of the compressor;

and the controller is configured to control the throttling communication assembly to communicate or cut off the oil return flow path according to the detection result of the current detection assembly.

2. The compressor system of claim 1, further comprising:

3. The compressor system of claim 2, wherein the temperature sensing assembly comprises:

the pre-throttling temperature sensor is arranged between the throttling communication assembly and the compressor;

and the temperature sensor after throttling is arranged between the throttling communication assembly and the gas-liquid separator.

4. The compressor system of claim 1, wherein the oil return flow path further comprises:

the filter is arranged between the inlet end of the oil return flow path and the throttling communication assembly.

5. The compressor system of any one of claims 1 to 4, wherein the throttle communication assembly includes an electronic expansion valve.

6. A multi-split air conditioner, comprising: a compressor system as claimed in any one of claims 1 to 5.

7. The control method for compressor oil return, which is applied to the multi-split air conditioner of claim 6, is characterized by comprising the following steps:

under the condition that an oil return flow path is communicated, acquiring a current value of the compressor;

8. The control method according to claim 7, wherein,

if the present current value is greater than a first current threshold, determining a control strategy for the throttled communication assembly, comprising:

9. The control method according to claim 8, characterized in that the obtaining of the first current threshold value includes:

10. The control method of claim 8, wherein the determining a control strategy for the throttle communication assembly based on a current temperature difference of the first temperature and the second temperature comprises:

if the current temperature difference is greater than a first temperature difference, a control strategy for the throttle communication assembly includes:

if the current temperature difference is less than or equal to a second temperature difference, a control strategy for the throttle communication assembly comprising:

11. The control method according to claim 10, characterized in that the increasing the opening degree of the throttle communication assembly includes:

12. The control method according to claim 11, characterized in that the determining an opening degree adjustment value for increasing the opening degree of the throttle communication assembly according to the present current value includes:

13. The control method according to claim 12, characterized in that the obtaining of the second current threshold value includes:

14. The control method according to any one of claims 7 to 13, characterized by further comprising:

15. A control device for compressor oil return, applied to the multi-split air conditioner of claim 6, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute the control method for compressor oil return of any one of claims 7 to 14 when the program instructions are executed.