CN211739554U

CN211739554U - Multi-split air conditioning system and oil balancing device thereof

Info

Publication number: CN211739554U
Application number: CN202020224828.6U
Authority: CN
Inventors: 项宇; 赵平; 曾荡; 韩艳春; 赵岩
Original assignee: Emerson Climate Technologies Suzhou Co Ltd
Current assignee: Copeland Suzhou Co Ltd
Priority date: 2020-02-27
Filing date: 2020-02-27
Publication date: 2020-10-23
Anticipated expiration: 2030-02-27

Abstract

The utility model relates to an oil balancing unit for many online air conditioning systems. This oil balancing unit includes: an oil balance pipe for communicating the oil sump in the first compressor with the oil sump in the second compressor; an oil separator mounted to the exhaust manifold; and an oil return line connected between the oil separator and the first compressor, through which the lubricating oil in the oil separator can be supplied to the first compressor. The utility model discloses still relate to the many online air conditioning systems who has above-mentioned oil balancing unit. The multi-split air conditioning system can effectively recover lubricating oil from exhaust gas and convey the lubricating oil to the compressor with the maximum risk of insufficient lubricating oil, and the risk of insufficient lubricating oil in the compressor is reduced through a simple structure. The multi-split air conditioning system can also detect the abnormal condition of the oil level in the compressor, provide alarm in time and take protective measures to prevent the compressor from being damaged.

Description

Multi-split air conditioning system and oil balancing device thereof

Technical Field

The utility model relates to a many online air conditioning systems, more specifically relates to many online air conditioning systems's the oily balancing unit between many compressors.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

The multi-split air conditioning system has higher system energy efficiency, can meet the requirement of higher comprehensive energy efficiency of the system, is popular in the air conditioning market, and is an ideal choice for multi-terminal systems of various office places, factories and families. A multi-split air conditioning system typically includes two or more compressors capable of operating in parallel. In the operation process of the multi-split air-conditioning system, the loads of the compressors may be different, the distribution of lubricating oil of the compressors may be unbalanced, the lubricating oil of some compressors is insufficient, and the lubricating oil of some compressors is too much, which easily causes damage to the compressors, affects the overall energy efficiency of the multi-split air-conditioning system, and even causes the multi-split air-conditioning system to be incapable of operating normally. Therefore, the balance of the lubricating oil between the compressors of the multi-split air conditioning system has been a design focus.

In the existing multi-split air conditioning system, there are two main ways to realize the balance of the lubricating oil among the compressors, one is a passive lubricating oil balance design, and the other is an active lubricating oil balance design. In the prior multi-split air conditioning system adopting the passive lubricating oil balance design, oil pools in a plurality of compressors are connected by adopting oil balance pipes, and lubricating oil flows from the oil pool in the compressor with higher internal pressure to the oil pool in the compressor with lower internal pressure through the oil balance pipes by utilizing the pressure difference in different compressors, so that the oil level difference is formed between the oil pools of adjacent compressors. This type of multi-split air conditioning system is simple in construction, but during operation, as long as there is a pressure difference between the internal pressures of the compressors whose oil sumps are connected to each other, the lubricating oil will flow all the time from the inside of the compressor whose internal pressure is high to the inside of the compressor whose internal pressure is low, even when the lubricating oil in the compressor whose internal pressure is high is insufficient, the risk of insufficient lubricating oil in the compressor whose internal pressure is high is great, and it is not possible to provide any alarm or guard against the insufficient lubricating oil. In the existing multi-split air conditioning system adopting the active lubricating oil balance design, each compressor is provided with an oil level detector for detecting the oil level of the lubricating oil in an oil pool in each compressor, and is further provided with an oil separator and a corresponding oil return pipeline, so that once the oil level detector of one compressor detects that the oil level of the oil pool in the compressor is lower than a preset oil level, the lubricating oil flows from the oil separator to the compressor through the corresponding oil return pipeline. The multi-split air conditioning system can supplement lubricating oil in time when the lubricating oil in the compressors is insufficient, but each compressor needs to be provided with an oil level detector and a corresponding oil return pipeline, so that the system is complex in structure and high in cost.

Accordingly, there remains a need for an improved oil balance design for multiple compressors of a multi-split air conditioning system.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to solve at least one of the above problems.

An aspect of the present invention is to provide an oil balancing device for a multi-split air conditioning system. The multi-split air conditioning system comprises a first compressor and a second compressor, wherein the exhaust port of the first compressor and the exhaust port of the second compressor are connected to an exhaust manifold in parallel. The oil balancing device includes: the oil balance pipe is used for communicating the oil pool in the first compressor with the oil pool in the second compressor, wherein the pressure of the oil pool in the first compressor is higher than that of the oil pool in the second compressor; an oil separator mounted to the exhaust manifold and configured to separate the lubricating oil from the exhaust of the first and second compressors; and an oil return line connected between the oil separator and the first compressor such that the lubricating oil in the oil separator can be supplied to the first compressor through the oil return line.

In one embodiment, the oil balancing device further comprises a sensor and a controller. A sensor is mounted on the first compressor and is configured to communicate with the controller. The controller determines an oil level state of an oil sump in the first compressor according to a detection result of the sensor, and controls a stop of the first compressor and the second compressor.

The controller is configured to: stopping the second compressor when the oil level of the oil sump of the first compressor is lower than the safe oil level; and stopping the first compressor if the oil level of the oil sump in the first compressor is still below the safe oil level after the second compressor is stopped for the first predetermined time.

In one embodiment, the controller triggers the warning device when the oil level of the oil sump of the first compressor is below a safe oil level.

In one embodiment, the oil balancing device further includes a solenoid valve disposed on the oil return line, and the controller is configured to selectively open or close the solenoid valve to establish or interrupt oil supply communication between the oil separator and the first compressor according to a detection result of the sensor.

The controller is configured to: opening the electromagnetic valve to allow the lubricating oil in the oil separator to flow into the first compressor when the oil level of the oil sump of the first compressor is lower than a normal oil level, wherein the normal oil level is higher than a safe oil level; when the oil level of the oil sump in the first compressor is higher than the normal oil level, the electromagnetic valve is closed so that the lubricating oil in the oil separator no longer flows into the first compressor.

The controller mechanism further causes: when the electromagnetic valve is in an open state and the duration of time during which the oil level of the oil sump in the first compressor is lower than the normal oil level exceeds a second predetermined time, it is determined that the oil level of the oil sump of the first compressor is lower than the safe oil level.

In one embodiment, the sensor is a fuel level sensor.

And the lubricating oil in the oil separator is conveyed to an air inlet port of the first compressor through an oil return pipeline or directly conveyed to an oil pool in the first compressor.

In one embodiment, the inlet port of the first compressor is connected to the inlet manifold via a first inlet manifold and the inlet port of the second compressor is connected to the inlet manifold via a second inlet manifold. The length of the fluid passage in the first intake manifold is less than the length of the fluid passage in the second intake manifold, and/or the pipe inner diameter of the first intake manifold is less than the pipe inner diameter of the second intake manifold, such that the pressure at which the oil sump in the first compressor is located is higher than the pressure at which the oil sump in the second compressor is located.

In one embodiment, the multi-split air conditioning system further includes one or more additional compressors disposed in parallel with the first compressor and the second compressor, an oil sump in the one or more additional compressors is in communication with an oil sump in the first compressor and the second compressor via an oil balance pipe, and the oil sump in the one or more additional compressors is at a lower pressure than the oil sump in the first compressor.

Another aspect of the utility model is to provide a many online air conditioning systems, this many online air conditioning systems include according to the utility model discloses an oil balancing unit.

Another aspect of the present invention is to provide an oil balance control method for a multi-split air conditioning system. The multi-split air conditioning system comprises a first compressor and a second compressor, wherein the pressure of an oil pool in the first compressor is higher than that of an oil pool in the second compressor. The oil balance control method comprises the following steps: separating the lubricating oil from the exhaust of the first and second compressors using an oil separator; supplying the lubricating oil in the oil separator to the first compressor through an oil return pipeline; and causing the lubricating oil in the first compressor to flow to the second compressor through the oil balance pipe.

The oil balance control method further includes detecting an oil level of an oil sump in the first compressor. And stopping the second compressor when the oil level of the oil pool in the first compressor is lower than the safe oil level, and stopping the first compressor if the oil level of the oil pool of the first compressor is still lower than the safe oil level after the second compressor is stopped for a first preset time.

The oil balance control method further includes: the method further includes interrupting oil supply communication between the oil separator and the first compressor when an oil level of an oil sump in the first compressor is higher than a normal oil level, and establishing the oil supply communication between the oil separator and the first compressor when the oil level of the oil sump in the first compressor is lower than the normal oil level.

When the duration in which the oil level of the oil sump in the first compressor is lower than the normal oil level exceeds a second predetermined time, it is determined that the oil level of the oil sump in the first compressor is lower than the safe oil level.

The utility model provides a modified is used for many online air conditioning system's oil balancing unit, has this oil balancing unit's many online air conditioning system and oil balance control method. According to the utility model discloses a many online air conditioning system can retrieve lubricating oil effectively in the exhaust of compressor to at first carry the lubricating oil of retrieving to the compressor that has the not enough biggest risk of lubricating oil, then with the help of the pressure differential between the pressure of the oil bath department in the compressor, make lubricating oil flow to other compressors, with simple structure greatly reduced the compressor appear the not enough risk of lubricating oil. Additionally, according to the utility model discloses a many online air conditioning system can also detect the oil level abnormal conditions in the compressor, provides the police dispatch newspaper in time and takes protective measures, prevents that the compressor from receiving the damage.

Drawings

Embodiments of the invention will be described below, by way of example only, with reference to the accompanying drawings. In the drawings, like features or components are designated with like reference numerals, and the drawings are not necessarily drawn to scale, and wherein:

fig. 1 illustrates a view of one compressor in a multi-split air conditioning system according to a first embodiment of the present invention;

fig. 2 is a plan view illustrating a plurality of compressors connected to one another of a multi-split air conditioning system according to a first embodiment of the present invention;

FIG. 3 shows a front view of the plurality of compressors of FIG. 2;

fig. 4 is a view illustrating one compressor in a multi-split air conditioning system according to a second embodiment of the present invention;

fig. 5 is a front view illustrating a plurality of compressors connected to one another of a multi-split air conditioning system according to a second embodiment of the present invention;

fig. 6 is a flowchart illustrating an oil balance control method of a multi-split air conditioning system according to a second embodiment of the present invention;

fig. 7 is a view illustrating one compressor in a multi-split air conditioning system according to a third embodiment of the present invention;

fig. 8 is a front view illustrating a plurality of compressors connected to one another of a multi-split air conditioning system according to a third embodiment of the present invention;

fig. 9 is a flowchart illustrating an oil balance control method of a multi-split air conditioning system according to a third embodiment of the present invention.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, like reference numerals indicate like or similar parts and features. The drawings are only schematic representations of the concepts and principles of the embodiments of the present invention, and do not necessarily show the specific dimensions and proportions of the various embodiments of the present invention. Certain features that are in certain figures may be shown exaggerated in detail in order to illustrate relevant details or structures of embodiments of the invention.

In the description of the embodiments of the present invention, the directional terms used in connection with "upper", "lower", "left" and "right" are used in the description of the upper, lower, left and right positions of the views shown in the drawings. In practical applications, the positional relationships of "up", "down", "left" and "right" used herein may be defined according to practical situations, and these relationships may be reversed.

The inventor finds that in a multi-split air conditioning system, the existing passive oil balancing device cannot well solve the problem of insufficient lubricating oil of a compressor, and cannot provide any alarm or protection for abnormal working conditions of insufficient lubricating oil, while the existing active oil balancing device is complex in overall structure and high in cost. For this reason, the present inventors have proposed an improved oil balancing device for a multi-split air conditioning system, which has a simple structure, is capable of effectively recovering lubricating oil from the discharge air of a compressor, and replenishing the recovered lubricating oil to the compressor having the greatest risk of insufficient lubricating oil first, and is capable of significantly reducing the risk of insufficient lubricating oil in the compressor by flowing the lubricating oil into other compressors through an oil balancing pipe by a pressure difference between pressures at which an oil sump in the compressor is located. Additionally, according to the utility model discloses a many online air conditioning system's oil balancing unit can also detect the oil level of the oil bath in the compressor with simple structure, can in time provide the police dispatch newspaper and take corresponding safeguard procedures to the unusual operating mode that lubricating oil is not enough in the compressor, reduces the risk that lubricating oil is not enough in the compressor, prevents that the compressor from damaging because of lubricating oil is not enough, prolongs the life of compressor. The multi-split air conditioning system and the oil balancing device thereof according to the present invention will be described with reference to the accompanying drawings.

Fig. 1 to 3 are views illustrating a compressor of an outdoor unit of a multi-split air conditioning system 100 according to a first embodiment of the present invention. The multi-split air conditioning system 100 may include two or more compressors connected in parallel, and the compressors may be compressors in one outdoor unit or compressors in a plurality of outdoor units connected in parallel. Fig. 1 illustrates a view of one compressor in a multi-split air conditioning system 100. As shown in fig. 1, the first compressor 10 includes a housing 11, a top cover 12, and a base 13. The housing 11 is sealingly engaged with the top cover 12 and the base 13, respectively, thereby defining a sealed interior space. The housing 11 is provided with an intake port 14 and a lubrication oil balance port 15. The top cover 12 is provided with an exhaust port 16. The refrigerant gas enters the internal space of the first compressor 10 through the inlet port 14, is compressed by the compression mechanism (not shown), and is discharged out of the first compressor 10 through the outlet port 16. The bottom of the inner space of the first compressor 10 is provided with an oil sump (not shown in the drawings) for lubricating oil, which is supplied to various components (e.g., a compression mechanism, a bearing housing, etc.) within the compressor for lubrication. After lubricating the components in the compressor, a part of the lubricating oil returns to the oil sump, and a part of the lubricating oil is carried into the compression chamber of the compression mechanism along with the refrigerant gas, and is discharged from the discharge port 16 along with the refrigerant gas after being compressed. The plurality of compressors of the outdoor unit of the multi-split air conditioning system 100 each have a structure similar to that described above, i.e., each is provided with an intake port, a discharge port, and a lubricant oil balance port.

Fig. 2 illustrates a plan view of two compressors of the multi-split air conditioning system 100 connected to each other, and fig. 3 illustrates a front view of fig. 2. In the drawings and the present example, only the connection between two compressors of the multi-split air conditioning system 100 is shown to schematically describe the oil balancing device between the compressors of the multi-split air conditioning system 100 according to the first embodiment of the present invention.

As shown in fig. 2 and 3, the

intake ports

14 and 24 of the first and

second compressors

10 and 20 of the multi-split air conditioning system 100 are connected to the intake manifold 30 in parallel. The intake manifold 30 is divided into a first intake branch 31 and a second intake branch 33 at a first junction T1. The first intake branch pipe 31 is connected to the intake port 14 of the first compressor 10, and the second intake branch pipe 33 is connected to the intake port 24 of the second compressor 20. The oil sump in the first compressor 10 is at a higher pressure than the oil sump in the second compressor 20. In this example, the first joint T1 is located substantially midway between the intake port 14 of the first compressor 10 and the intake port 24 of the second compressor 20, the length of the fluid passage in the first intake branch 31 is substantially equal to the length of the fluid passage in the second intake branch 33, but the pipe inner diameter of the first intake branch 31 is smaller than the pipe inner diameter of the second intake branch 33, so that the pressure in the intake pressure zone in the casing 11 of the first compressor 10 is higher than the pressure in the intake pressure zone in the casing 21 of the second compressor 20, and therefore the pressure at the oil sump in the first compressor 10 is higher than the pressure at the oil sump in the second compressor 20. However, the present invention is not limited thereto, and in other examples according to the present invention, the first intake manifold 31 and the second intake manifold 33 may be provided to have the same pipe inner diameter, and the length of the fluid passage in the first intake manifold 31 is smaller than the length of the fluid passage in the second intake manifold 33, still enabling the internal pressure in the casing of the first compressor 10 to be higher than the internal pressure in the casing of the second compressor 20. In addition, the first compressor 10 and the second compressor 20 may have the oil sump in the first compressor 10 at a higher pressure than the oil sump in the second compressor 20 due to different compressor types and parameters. The first compressor 10 and/or the second compressor 20 may be a fixed frequency compressor, an inverter compressor, or a variable capacity compressor.

The

discharge ports

16 and 26 of the first and

second compressors

10 and 20 are connected in parallel to a discharge manifold 40. The discharge port 16 of the first compressor 10 is connected to a first discharge branch pipe 41, the discharge port 26 of the second compressor 20 is connected to a second discharge branch pipe 43, and the first discharge branch pipe 41 and the second discharge branch pipe 43 are merged to one end of a discharge manifold 40 at a second junction T2.

The oil balancing device between the first compressor 10 and the second compressor 20 includes an oil balancing pipe 50. The oil balance pipe 50 connects the oil balance port 15 of the first compressor 10 and the oil balance port (not shown in the drawings) of the second compressor 20 to each other such that the oil sump in the first compressor 10 and the oil sump in the second compressor 20 communicate with each other through the oil balance pipe 50. Due to the pressure difference between the pressures at which the oil sumps in the first and

second compressors

10 and 20 are located, the lubricating oil in the oil sump in the first compressor 10 having the higher pressure flows through the oil balance pipe 50 to the oil sump in the second compressor 20 having the lower pressure. The oil level in the oil sump in the first compressor 10 is lower than the oil level in the oil sump of the second compressor 20. Therefore, the first compressor 10 is more likely to suffer from a shortage of lubricating oil than the second compressor 20.

The oil balancing arrangement between the first compressor 10 and the second compressor 20 further comprises an oil separator 60 and an oil return line 70. An oil separator 60 is provided on the discharge side of the compressor, mounted to the discharge manifold 40. As shown in fig. 2 and 3, the oil separator 60 has an inlet 61, a refrigerant gas outlet 63, and a lubricating oil outlet 65. The inlet 61 is connected to the exhaust manifold 40 and the lubricant outlet 65 is connected to the return line 70. The discharge gas discharged from the first and

second compressors

10 and 20 flows into the oil separator 60 through the discharge manifold 40 and the inlet 61. The refrigerant gas in the exhaust gas is separated from the lubricating oil in the oil separator 60, the refrigerant gas is discharged from the refrigerant gas outlet 63 of the oil separator 60, and the lubricating oil is collected at the bottom of the oil separator 60, flows into the oil return line 70 from the lubricating oil outlet 65 of the bottom, and flows into the first compressor 10. In the present example, the other end of the oil return line 70 is connected to the first intake manifold 31, so that the lubricating oil in the oil separator 60 is delivered to the intake port 14 of the first compressor 10 via the oil return line 70, enters the first compressor 10 from the intake port 14, and then is collected in the oil sump in the first compressor 10. Alternatively, the other end of the oil return line 70 may also be directly connected to the housing 11 of the first compressor 10 to supply the lubricating oil in the oil separator 60 directly to the oil sump in the first compressor 10.

In the multi-split air conditioning system 100 according to the first embodiment of the present invention, the oil balancing means includes the oil balancing pipe 50 connecting the oil balancing ports of the respective compressors to each other, the oil separator 60 provided at the discharge manifold 40 of the compressors, and the oil return line 70. By connecting the oil separator 60 to the discharge manifold 40 of the compressor, it is possible to efficiently recover the lubricating oil from the discharge of the compressor and supply the recovered lubricating oil first to the first compressor 10 through the oil return line 70, i.e., first to the compressor most likely to suffer from a shortage of lubricating oil, and then, by means of the pressure difference between the pressures at which the oil sumps connected to each other are located, to flow the lubricating oil from the oil sump in the first compressor 10 having a higher pressure to the oil sump in the second compressor 20 having a lower pressure through the oil balance pipe 50, it is possible to significantly reduce the risk of the compressor of the multi-split air conditioning system 100 suffering from a shortage of lubricating oil and to avoid the compressor from being damaged due to the shortage of lubricating oil. Preferably, the oil balancing means only needs to provide an oil return line 70 from the oil separator 60 to the first compressor 10, and does not need to provide an oil return line from the oil separator 60 to the remaining compressors, thereby enabling the structure of the system to be simplified. In addition, since the lubricating oil flows from the oil separator 60 into the first compressor 10 and then flows into the second compressor 20, even when the models of the first compressor 10 and the second compressor 20 are different, a complicated matching test is not required, and thus, the test development time for oil balance management of the multi-split air conditioning system 100 can be shortened. In addition, by directly recovering the lubricating oil from the exhaust manifold of the compressor, the circulation path of the lubricating oil in the multi-split air conditioning system 100 can be significantly shortened, the lubricating oil is prevented from flowing to other parts (such as an evaporator and a condenser) of the air conditioning system, sufficient lubricating oil can be ensured to be kept in the compressor, and the risk of insufficient lubricating oil in the compressor can be reduced.

The above description is according to the utility model discloses a many online air conditioning system 100's of first embodiment oil balancing unit between the compressor, this oil balancing unit can supply the lubricating oil of retrieving at first to the biggest compressor of the insufficient risk of lubricating oil to simple structure greatly reduced many online air conditioning system 100's compressor the risk that lubricating oil is insufficient appears.

Fig. 4 and 5 illustrate views of a compressor of a multi-split air conditioning system 200 and an oil balancing device thereof according to a second embodiment of the present invention. The configuration of the compressor of the multi-split air conditioning system 200 according to the second embodiment of the present invention is substantially the same as the configuration of the compressor of the multi-split air conditioning system 100 according to the first embodiment of the present invention, and the difference is only in the arrangement of the first compressor 10A of the multi-split air conditioning system 200 and the oil balancing device. In the drawings, the same components as those in the multi-split air conditioning system 100 are denoted by the same reference numerals, and the description thereof is not repeated. Hereinafter, only the difference between the multi-split air conditioning system 200 and the multi-split air conditioning system 100 according to the present invention will be described.

Fig. 4 illustrates a view of one compressor of the multi-split air conditioning system 200. As shown in fig. 4, the first compressor 10A includes an intake port 14, a lube oil balance port 15, and a discharge port 16. In addition, the first compressor 10A further includes a sensor mounting port 17, and the sensor mounting port 17 is used for mounting a sensor 80 (see fig. 5). The second compressor of the multi-split air conditioning system 200 is the same as the second compressor of the multi-split air conditioning system 100.

Fig. 5 illustrates a connection between the first compressor 10A and the second compressor 20 of the multi-split air conditioning system 200, and illustrates an oil balancing device of the multi-split air conditioning system 200. As shown in fig. 5, the oil balancing device of the multi-split air conditioning system 200 includes an oil balancing pipe 50, an oil separator 60, and an oil return line 70. The oil balancing device further includes a sensor 80 and a controller C1, the sensor 80 communicating with the controller C1 to provide detection of an abnormal state of the oil level of the oil sump within the compressor and to alert and take corresponding protective measures of the abnormal state of the oil level of the oil sump within the compressor. The sensor 80 is installed in the sensor installation port 17 of the first compressor 10A. In the present example, the sensor 80 is an oil level sensor installed at a height of a safety oil level of an oil sump in the compressor 10A for detecting the oil level of the oil sump in the first compressor 10A. If the oil level of the oil sump in the compressor is below the safe oil level, the compressor will be damaged if it is operated in this state. The controller C1 may be a separate controller dedicated to the oil balancing device or may be one of the control modules in the overall controller of the multi-split air conditioning system 200. The sensor 80 is in communication with the controller C1. The sensor 80 sends the detected oil level signal to the controller C1, and the controller C1 performs corresponding control based on the received oil level signal, for example, triggering an alarm signal, shutting down the first compressor 10A and/or the second compressor 20, and the like, as indicated by the dotted lines in fig. 5. Alternatively, the sensor 80 may be a sensing device for measuring other parameters of the compressor, the sensor 80 sending the detected parameters to the controller C1, and the controller C1 calculating the oil level of the oil sump in the first compressor 10A based on the received detected parameters.

Fig. 6 illustrates a flowchart of an oil balance control method performed by the controller C1 of the multi-split air conditioning system 200. First, in step S10, the multi-split air conditioning system 200 is turned on. Next, in step S20, it is determined whether or not the sensor 80 detects that the oil level of the oil sump in the first compressor 10A is lower than the safe oil level. If it is detected that the oil level in the oil sump of the first compressor 10A is lower than the safe oil level and the lubricating oil in the oil sump is insufficient, the controller C1 of the multi-split air conditioning system 200 triggers an alarm device to send an alarm signal. The alarm signal may be a visually variable light or an audibly discernable sound. Then, in step S30, the compressor is checked and the lubricating oil is replenished. If it is not detected in step S20 that the oil sump oil level in the first compressor 10A is lower than the safety oil level, indicating that the lubricating oil in the compressor is sufficient, the controller C1 operates the first and

second compressors

10A and 20 of the multi-split air conditioning system 200 in step S40. Upon detecting in step S50 that the oil level of the oil sump within the first compressor 10A is lower than the safety oil level during the operation of the first and

second compressors

10A and 20, the controller C1 stops the compressors in step S60. Specifically, the controller C1 first stops the second compressor 20, and then stops the first compressor 10A if it is still detected that the oil level of the oil sump in the first compressor 10A is below the safe oil level after the second compressor 20 is stopped for a first predetermined time. Then, the compressor is checked, and the lubricating oil is replenished as shown in step S30.

In the multi-split air conditioning system 200 according to the second embodiment of the present invention, the oil balancing device includes the oil balancing pipe 50, the oil separator 60, the oil return line 70, the sensor 80, and the controller C1. Similar to the multi-split air conditioning system 100 of the first embodiment, the oil balancing device of the multi-split air conditioning system 200 can reduce the risk of insufficient lubrication oil of the compressor with a simple structure. In addition, the oil balancing device of the multi-split air conditioning system 200 can also detect the oil level of the oil sump in the first compressor 10A and take corresponding measures based on the detection result, and even if the lubricating oil in the oil sump in the first compressor 10A is insufficient, the alarm device can be timely triggered to give an alarm signal, and the compressor can be timely stopped, so that the compressor is protected from being damaged.

Fig. 7 and 8 are views illustrating a compressor of a multi-split air conditioning system 300 and an oil balancing device thereof according to a third embodiment of the present invention. The configuration of the compressor of the multi-split air conditioning system 300 according to the third embodiment of the present invention is substantially the same as the configuration of the compressor of the multi-split air conditioning system 100 according to the first embodiment of the present invention, and is distinguished only by the first compressor 10B of the multi-split air conditioning system 300 and the arrangement of the oil balancing device. In the drawings, the same components as those in the multi-split air conditioning system 100 are denoted by the same reference numerals, and the description thereof is not repeated. Hereinafter, only the difference between the multi-split air conditioning system 300 and the multi-split air conditioning system 100 according to the present invention will be described.

Fig. 7 illustrates a view of one compressor of the multi-split air conditioning system 300. As shown in fig. 7, the first compressor 10B includes an intake port 14, a lube oil balance port 15, and a discharge port 16. In addition, the first compressor 10B further includes a sensor mounting opening 18, and the sensor mounting opening 18 is used for mounting a sensor 81 (see fig. 8). The second compressor of the multi-split air conditioning system 300 is the same as the second compressor of the multi-split air conditioning system 100.

Fig. 8 illustrates a connection between the first compressor 10B and the second compressor 20 of the multi-split air conditioning system 300, and illustrates an oil balancing device of the multi-split air conditioning system 300. As shown in fig. 8, the oil balancing device of the multi-split air conditioning system 300 includes an oil balancing pipe 50, an oil separator 60, and an oil return line 70. The oil balancing device further includes a sensor 81, an electromagnetic valve 90, and a controller C2, provides detection of an oil level abnormal state of the first compressor 10B, and alarms the oil level abnormal state of the compressor and takes corresponding measures. The sensor 81 is installed in the sensor installation port 18 of the first compressor 10B. In the present example, the sensor 81 is an oil level sensor installed at a height of a normal oil level of the oil sump of the first compressor 10B for detecting the oil level of the oil sump of the first compressor 10B. The normal oil level of the oil sump is higher than the safe oil level. A solenoid valve 90 is installed in the return line 70 to block or conduct the return line 70. The controller C2 may be a separate controller dedicated to the oil balancing device or may be one of the control modules in the overall controller of the multi-split air conditioning system 300. The sensor 81 is in communication with the controller C2. The sensor 81 transmits the detected oil level signal to the controller C2, and the controller C2 performs corresponding control, for example, triggering an alarm signal, opening or closing the electromagnetic valve 90, stopping the first compressor 10B and/or the second compressor 20, etc., based on the received oil level signal, as indicated by the dotted line in fig. 8. Alternatively, the sensor 81 may be a sensing device for measuring other parameters of the compressor, the sensor 81 sends the detected parameters to the controller C2, and the controller C2 calculates the oil level of the oil sump of the first compressor 10B based on the received detected parameters.

Fig. 9 illustrates a flowchart of a control method performed by the controller C2 of the multi-split air conditioning system 300. First, in step S110, the multi-split air conditioning system 300 is turned on. Next, in step S120, it is determined whether the sensor 81 detects that the oil level of the oil sump in the first compressor 10B is lower than the normal oil level. If the oil level of the oil sump in the first compressor 10B is detected to be lower than the normal oil level, the controller C2 of the multi-split air conditioning system 300 triggers an alarm device to send an alarm signal. The alarm signal may be a visually variable light or an audibly discernable sound. Then, in step S130, the state of the compressor is checked, and the lubricating oil is replenished. If it is not detected in step S120 that the oil level of the oil sump in the first compressor 10B is lower than the normal oil level, indicating that the lubricating oil in the compressor is sufficient, the controller C2 operates the first and

second compressors

10B and 20 of the multi-split air conditioning system 300 and opens the solenoid valve 90 in step S140. During the operation of the first and

second compressors

10B and 20, when it is detected in step S150 that the oil level of the oil sump in the first compressor 10B exceeds the normal oil level, the controller C2 closes the electromagnetic valve 90 and blocks the oil return line 70 in step S160, thereby blocking the oil supply communication between the oil separator 60 and the first compressor 10B and preventing the lubricating oil in the oil separator 60 from being supplied to the first compressor 10B. If it is detected in step S170 that the oil level of the oil sump in the first compressor 10B is lower than the normal oil level, the controller C2 opens the electromagnetic valve 90 to conduct the oil return line 70, thereby bringing the oil separator 60 into oil supply communication with the first compressor 10B so that the lubricating oil in the oil separator 60 is supplied to the first compressor 10B in step S180. If it is detected in step S190 that the duration of time during which the oil level of the oil sump in the first compressor 10B is lower than the normal oil level exceeds the second predetermined time, it is determined that the oil level of the oil sump in the first compressor 10B is lower than the safe oil level, and then the controller C2 stops the compressor in step S200. Specifically, the controller C2 stops the second compressor 20 first, and then stops the first compressor 10B if it is still detected that the oil level of the oil sump of the first compressor 10B is lower than the normal oil level after the second compressor 20 is stopped for a predetermined time. Then, the compressor condition is checked and the lubricating oil is replenished as shown in step S130. If it is detected in step S190 that the duration in which the oil level of the oil sump in the first compressor 10B is lower than the normal oil level does not exceed the second predetermined time, it means that the first compressor 10B can be operated by supplementing the lubricating oil from the oil separator 60, and thus the first compressor 10B and the second compressor 20 are kept operated, and it returns to step S150 to always detect the oil level of the oil sump in the first compressor 10B.

In the multi-split air conditioning system 300 according to the third embodiment, the oil balancing means includes the oil balancing pipe 50, the oil separator 60, the oil return line 70, the sensor 81, the solenoid valve 90, and the controller C2. Similar to the multi-split air conditioning system 100 of the first embodiment, the oil balancing device of the multi-split air conditioning system 300 can reduce the risk of insufficient lubrication oil of the compressor with a simple structure. In addition, the oil balancing device of the multi-split air conditioning system 300 can also detect the oil level of the oil pool in the first compressor 10B and communicate with the controller C2, control the oil return requirement of the compressor according to the oil level of the oil pool in the first compressor 10B, and can estimate whether the first compressor 10B may have insufficient lubricating oil according to the duration that the oil level of the oil pool of the first compressor 10B is lower than the normal oil level, so that even if the oil level of the oil pool of the first compressor 10B is insufficient, the alarm device can be triggered to send an alarm signal in time, and the compressor can be stopped in time, thereby protecting the compressor from damage.

The above illustrates a multi-split air conditioning system according to a preferred embodiment of the present invention. In the preferred embodiment shown above, the oil balancing device of the multi-split air conditioning system includes an oil separator provided on the discharge header of the compressor, and the lubricating oil in the oil separator is first supplied to the compressor with the greatest risk of lubricant shortage through the oil return line, so that the compressor with the lowest oil level can first supply the lubricating oil for replenishment, and the risk of lubricant shortage occurring in the compressor can be reduced with a simple structure. In the multi-split air conditioning system described above, only the oil return line from the oil separator to the compressor with the greatest risk of insufficient lubricating oil is provided, and the lubricating oil flows to the other compressors by the difference in internal pressure of the compressors, so that the structural design of the system can be simplified, the cost can be reduced, and the test development time for oil balance management can be shortened. However, the present invention is not limited thereto, and in other examples according to the present invention, the oil balancing device of the multi-split air conditioning system may also be provided with an oil return line from the oil separator to another compressor.

The oil balancing device of the multi-split air conditioning system according to the present invention has been described above by taking the configuration in which two compressors are connected in parallel as an example. As described above, the multi-split air conditioning system may include more compressors, and the oil balancing device may still achieve oil balancing between the compressors as described above. For example, the multi-split air conditioning system may further include one or more additional compressors, in addition to the first and second compressors, in which oil sumps in the additional compressors are communicated with the oil sumps in the first and second compressors through oil balance pipes, and the oil sumps in the additional compressors are each at a lower pressure than the oil sump in the first compressor. In this configuration it is still possible to first supply the lubricating oil to the first compressor, which is at the greatest risk of a shortage of lubricating oil, and to let the lubricating oil flow from the first compressor to the other compressors by means of the pressure difference between the pressures at which the oil sump in the compressor is located.

Here, the exemplary embodiments of the present invention have been described in detail, but it should be understood that the present invention is not limited to the specific embodiments described and illustrated in detail above. Numerous modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention. All such variations and modifications are intended to fall within the scope of the present invention. Moreover, all the components described herein may be replaced by other technically equivalent components.

Claims

1. An oil balancing device for a multi-split air conditioning system including a first compressor and a second compressor, a discharge port of the first compressor and a discharge port of the second compressor being connected in parallel to a discharge manifold,

characterized in that the oil balancing device comprises:

an oil balance pipe that communicates an oil sump in the first compressor and an oil sump in the second compressor with each other, wherein the oil sump in the first compressor is at a higher pressure than the oil sump in the second compressor;

an oil separator mounted to the exhaust manifold and configured to separate lubricating oil from the exhaust of the first and second compressors; and

an oil return line connected between the oil separator and the first compressor such that lubricating oil in the oil separator can be supplied to the first compressor via the oil return line.

2. The oil balancing device for a multi-split air conditioning system as claimed in claim 1, further comprising a sensor mounted on the first compressor and configured to communicate with the controller, and a controller determining an oil level state of an oil sump in the first compressor according to a detection result of the sensor and controlling a stop of the first and second compressors.

3. The oil balancing device for a multi-split air conditioning system as set forth in claim 2, wherein the controller is configured to:

stopping the second compressor when an oil level of an oil sump within the first compressor is below a safe oil level; and

stopping the first compressor if an oil level of an oil sump within the first compressor remains below the safe oil level after the second compressor is stopped for a first predetermined time.

4. The oil balancing device for a multi-split air conditioning system as claimed in claim 3, wherein the controller triggers an alarm device when an oil level of an oil sump in the first compressor is lower than a safety oil level.

5. The oil balancing device for a multi-split air conditioning system as set forth in claim 3, further comprising a solenoid valve disposed on the oil return line, the controller being configured to selectively open or close the solenoid valve to establish or interrupt oil supply communication between the oil separator and the first compressor according to a detection result of the sensor.

6. The oil balancing device for a multi-split air conditioning system as set forth in claim 5, wherein the controller is configured to:

opening the electromagnetic valve to allow the lubricating oil in the oil separator to flow into the first compressor when the oil level of the oil sump in the first compressor is lower than a normal oil level, wherein the normal oil level is higher than the safety oil level;

when the oil level of the oil sump in the first compressor is higher than the normal oil level, the electromagnetic valve is closed so that the lubricating oil in the oil separator no longer flows into the first compressor.

7. The oil balancing apparatus for a multi-split air conditioning system as set forth in claim 6, wherein the controller is further configured to:

determining that the oil level of the oil sump in the first compressor is lower than the safe oil level when the electromagnetic valve is in the open state and the duration in which the oil level of the oil sump in the first compressor is lower than the normal oil level exceeds a second predetermined time.

8. An oil balancing device for a multi-split air conditioning system according to any one of claims 1 to 7, wherein the lubricating oil in the oil separator is delivered to an intake port of the first compressor or directly to an oil sump in the first compressor via the oil return line.

9. The oil balancing device for a multi-split air conditioning system according to any one of claims 1 to 7, wherein the intake port of the first compressor is connected to an intake manifold through a first intake branch pipe, and the intake port of the second compressor is connected to the intake manifold through a second intake branch pipe,

the length of the fluid channel in the first air inlet branch pipe is smaller than that of the fluid channel in the second air inlet branch pipe, and/or the pipe inner diameter of the first air inlet branch pipe is smaller than that of the second air inlet branch pipe, so that the pressure of an oil pool in the first compressor is higher than that of the oil pool in the second compressor.

10. An oil balancing device for a multi-split air conditioning system according to any one of claims 1 to 7, further comprising one or more additional compressors disposed in parallel with the first and second compressors, wherein an oil sump in the one or more additional compressors is in communication with an oil sump in the first and second compressors via the oil balancing pipe, and wherein the oil sump in the one or more additional compressors is at a lower pressure than the oil sump in the first compressor.

11. A multi-split air conditioning system, characterized in that it comprises an oil balancing device according to any one of claims 1 to 10.