阅读说明：本技术 一种多联机快速充注冷油的方法和制冷系统 (Method for rapidly filling cold oil into multi-split air conditioner and refrigerating system ) 是由 杨亚朋 李朝珍 严宁 万胜冬 施远 于 2021-07-20 设计创作，主要内容包括：本发明涉及多联机空调技术领域,且公开了一种多联机快速充注冷油的方法和制冷系统,包括压缩机,所述压缩机一端固定连接有出口a,所述出口a一端通过第一连接铜管与入口m固定连接,所述入口m一端固定连接有油分离器,所述油分离器一端固定连接有出口n,所述出口n一端通过第四连接铜管与室外冷凝器固定连接,所述室外冷凝器一端通过第六连接铜管与液体截止阀活动连接,所述液体截止阀一端固定连接有室内机；这种设置目的是对一种多联机空调室外机快速充注压缩机冷冻油方法的改进,对多联机空调制冷系统进行优化,提高多联机生产时充注冷冻油的效率,保证油分离器和气液分离中都有存油,为多联机空调系统稳定运行提供保障。(The invention relates to the technical field of multi-split air conditioners and discloses a method for quickly filling cold oil into a multi-split air conditioner and a refrigerating system, wherein the method comprises a compressor, one end of the compressor is fixedly connected with an outlet a, one end of the outlet a is fixedly connected with an inlet m through a first connecting copper pipe, one end of the inlet m is fixedly connected with an oil separator, one end of the oil separator is fixedly connected with an outlet n, one end of the outlet n is fixedly connected with an outdoor condenser through a fourth connecting copper pipe, one end of the outdoor condenser is movably connected with a liquid stop valve through a sixth connecting copper pipe, and one end of the liquid stop valve is fixedly connected with an indoor unit; the method aims to improve the method for rapidly filling the compressor refrigeration oil into the outdoor unit of the multi-split air conditioner, optimize the refrigeration system of the multi-split air conditioner, improve the efficiency of filling the refrigeration oil during the production of the multi-split air conditioner, ensure that oil is stored in an oil separator and gas-liquid separation, and provide guarantee for the stable operation of the multi-split air conditioner.)

1. A method for rapidly filling cold oil by a multi-split air conditioner and a refrigerating system comprise a compressor (1), and are characterized in that: one end of the compressor (1) is fixedly connected with an outlet a (101), one end of the outlet a (101) is fixedly connected with an inlet m (31) through a first connecting copper pipe (21), one end of the inlet m (31) is fixedly connected with an oil separator (3), one end of the oil separator (3) is fixedly connected with an outlet n (32), one end of the outlet n (32) is fixedly connected with an outdoor condenser (8) through a fourth connecting copper pipe (24), one end of the outdoor condenser (8) is movably connected with a liquid stop valve (11) through a sixth connecting copper pipe (26), one end of the liquid stop valve (11) is fixedly connected with an indoor unit (15), one end of the sixth connecting copper pipe (26) is fixedly connected with a one-way valve (10) and positioned at the left end and the right end of the one-way valve (10), one end of the sixth connecting copper pipe (26) is fixedly connected with a fifth connecting copper pipe (25), the air conditioner is characterized in that one end of a fifth connecting copper pipe (25) is fixedly connected with an electronic expansion valve (9), one end of a fourth connecting copper pipe (24) is fixedly connected with a seventh connecting copper pipe (27), one end of the seventh connecting copper pipe (27) is fixedly connected with a Y-shaped tee (6), one end of the Y-shaped tee (6) is fixedly connected with an oil return capillary needle valve (5), one end of the seventh connecting copper pipe (27) is fixedly connected with a normally closed air bypass electromagnetic valve (7), one end of the seventh connecting copper pipe (27) is fixedly connected with a third connecting copper pipe (23), one end of the third connecting copper pipe (23) is movably connected with a gas stop valve (12), one end of the gas stop valve (12) is fixedly connected with an indoor unit (15), one end of the third connecting copper pipe (23) is fixedly connected with an inlet x (131), and one end of the inlet x (131) is fixedly connected with a gas-liquid separator (13), one end of the gas-liquid separator (13) is fixedly connected with an outlet y (132), one end of the outlet y (132) is fixedly connected with a second connecting copper pipe (22), one end of the second connecting copper pipe (22) is fixedly connected with an inlet b (102), and one end of the inlet b (102) is fixedly connected with a compressor (1).

2. A multi-split quick-charging cold oil method and a refrigerating system as claimed in claim 1, wherein: the first connecting copper pipe (21), the second connecting copper pipe (22), the third connecting copper pipe (23), the fourth connecting copper pipe (24), the fifth connecting copper pipe (25), the sixth connecting copper pipe (26) and the seventh connecting copper pipe (27) are connected with refrigeration accessories through brazing.

3. A multi-split quick-charging cold oil method and a refrigerating system as claimed in claim 1, wherein: the third connecting copper pipe (23) and the sixth connecting copper pipe (26) are connected with the liquid stop valve (11) and the gas stop valve (12) through threads.

4. A multi-split quick-charging cold oil method and a refrigerating system as claimed in claim 1, wherein: and a gas separation oil return hole (14) is formed in one end of the gas-liquid separator (13).

5. A multi-split quick-charging cold oil method and a refrigerating system as claimed in claim 4, wherein: one end of the oil separator (3) is fixedly connected with an oil outlet f (33), one end of the oil outlet f (33) is fixedly connected with an oil return capillary tube (4), and one end of the oil return capillary tube (4) is fixedly connected with a second connecting copper tube (22).

6. A method for rapidly charging cold oil on-line and a use method of a refrigerating system, comprising the method for rapidly charging cold oil on-line and the refrigerating system as claimed in any one of claims 1 to 5, characterized in that: the method comprises the following steps:

s1, filling cold oil: in the refrigeration cycle during the refrigeration operation of the outdoor unit, under the outdoor side refrigeration operation environment temperature, the refrigerant of the outdoor unit enters the oil separator (3) from the inlet m (31) of the oil separator (3) after passing through the first connecting copper pipe (21) through the high-temperature and high-pressure oil mist mixed refrigerant gas discharged from the outlet a (101) of the compressor (1), the high-temperature and high-pressure oil mist mixed refrigerant in the oil separator (3) is subjected to oil mist separation, lubricating oil enters the bottom of the oil separator (3) along the inner wall surface of the oil separator (3), the high-temperature and high-pressure refrigerant gas is arranged on the upper part of the oil separator (3), the high-temperature and high-pressure refrigerant gas flows out from the outlet n (32) of the oil separator (3), the lubricating oil at the bottom of the oil separator (3) returns from the oil outlet f (33) through the oil return capillary tube (4), and the high-temperature and high-pressure refrigerant gas from the oil separator (3) enters the outdoor condenser (8) for heat release and condensation, condensed liquid refrigerant flows through an electronic expansion valve (9) and a one-way valve (10) at the same time, then the liquid refrigerant enters each indoor unit through a liquid stop valve (11), the electronic expansion valve (9) throttles, the throttled refrigerant absorbs heat in evaporators in each indoor unit to realize refrigeration of each indoor unit, the refrigerant flowing out of each indoor unit enters an inlet x (131) of a gas-liquid separator (13) through a gas stop valve (12) to perform gas-liquid separation, the separated low-temperature and low-pressure refrigerant gas flows out of an outlet y (132) of the gas-liquid separator (13) to enter an inlet b (102) of a compressor (1) to be compressed by the compressor (1) to realize a refrigeration cycle, a normally closed gas bypass electromagnetic valve (7) is electrically bypassed when the high-low pressure difference of a multi-split air conditioning system is large to play a role in balancing system pressure, and a lubricating oil in the oil separator (3) is returned from an oil outlet f (33) of the oil separator (3) by an oil return capillary tube (4) in real time, the lubricating oil is sucked into an inlet b (102) of the compressor (1) to lubricate the compressor (1), and a bottom gas-liquid separation oil return hole (14) in the gas-liquid separator (13) sucks a small amount of refrigerating oil at the bottom of the gas-liquid separator (13) to the compressor (1).

S2, improving efficiency: when the multi-split air conditioner outdoor unit is produced, the normally closed gas bypass electromagnetic valve (7) is electrified, the oil separator (3) and the gas-liquid separator (13) are in a communicated state, at the moment, the compressor refrigeration oil is filled through the oil return needle valve (5) interface, the compressor refrigeration oil is introduced into the oil separator (3) and the gas-liquid separator (13) through the Y-shaped tee joint (6) after entering the oil return needle valve (5), the amount of the compressor refrigeration oil filled in the oil separator (3) and the gas-liquid separator (13) is equivalent, and the accuracy production efficiency of the filling of the compressor refrigeration oil is improved.

Technical Field

The invention relates to the technical field of multi-split air conditioners, in particular to a method for rapidly filling cold oil into a multi-split air conditioner and a refrigerating system.

Background

The multi-connected air conditioning unit is called as multi-connected unit for short, the VRV system, the VRF system and GB/T18837-.

The common multi-split air conditioning system in the society is complex, and the refrigerant oil of the compressor needs to be filled twice from the high-pressure end and the low-pressure end respectively during the production of the multi-split air conditioning system, so that the multi-split air conditioning system is not obviously improved.

Disclosure of Invention

Technical problem to be solved

The invention provides a method for rapidly filling cold oil in a multi-split air conditioner and a refrigeration system, aiming at the defects of the prior art, and the method has the advantages that the method can rapidly and accurately fill the compressor refrigeration oil, can simultaneously fill the compressor refrigeration oil into an oil separator and a gas-liquid separator, is simple and stable, and solves the problems that the common multi-split air conditioner system is complex, and the compressor refrigeration oil needs to be respectively filled twice from a high-pressure end and a low-pressure end during the production of the multi-split air conditioner.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a method for quickly filling cold oil in a multi-split air conditioner and a refrigerating system comprise a compressor, wherein one end of the compressor is fixedly connected with an outlet a, one end of the outlet a is fixedly connected with an inlet m through a first connecting copper pipe, one end of the inlet m is fixedly connected with an oil separator, one end of the oil separator is fixedly connected with an outlet n, one end of the outlet n is fixedly connected with an outdoor condenser through a fourth connecting copper pipe, one end of the outdoor condenser is movably connected with a liquid stop valve through a sixth connecting copper pipe, one end of the liquid stop valve is fixedly connected with an indoor unit, one end of the sixth connecting copper pipe is fixedly connected with a one-way valve, one end of the sixth connecting copper pipe is fixedly connected with a fifth connecting copper pipe at the positions of the left end and the right end of the one-way valve, one end of the fifth connecting copper pipe is fixedly connected with an electronic expansion valve, one end of the fourth connecting copper pipe is fixedly connected with a seventh connecting copper pipe, the utility model discloses a compressor, including seventh connection copper pipe one end fixedly connected with Y type tee bend, Y type tee bend one end fixedly connected with oil return capillary needle valve, seventh connection copper pipe one end fixedly connected with normal close type gas bypass solenoid valve, seventh connection copper pipe one end fixedly connected with third connection copper pipe, copper pipe one end swing joint has gaseous stop valve is connected to the third, gaseous stop valve one end fixedly connected with indoor set, copper pipe one end fixedly connected with entry x is connected to the third, entry x one end fixedly connected with vapour and liquid separator, vapour and liquid separator one end fixedly connected with export Y, export Y one end fixedly connected with second connection copper pipe, copper pipe one end fixedly connected with entry b is connected to the second, entry b one end fixedly connected with compressor.

Preferably, the first connecting copper pipe, the second connecting copper pipe, the third connecting copper pipe, the fourth connecting copper pipe, the fifth connecting copper pipe, the sixth connecting copper pipe and the seventh connecting copper pipe are connected with the refrigeration fitting by brazing.

Preferably, the third connecting copper pipe and the sixth connecting copper pipe are connected with the liquid stop valve and the gas stop valve through threads.

Preferably, an air separation oil return hole is formed in one end of the air-liquid separator.

Preferably, one end of the oil separator is fixedly connected with an oil outlet f, one end of the oil outlet f is fixedly connected with an oil return capillary tube, and one end of the oil return capillary tube is fixedly connected with a second connecting copper tube.

A method for rapidly charging cold oil on-line and a use method of a refrigeration system, comprising the method for rapidly charging cold oil on-line and the refrigeration system as claimed in any one of claims 1 to 5, comprising the following steps:

s1, filling cold oil: the refrigeration cycle is carried out when the outdoor unit is in refrigeration operation, the refrigerant of the outdoor unit passes through a high-temperature high-pressure oil mist mixed refrigerant gas discharged from an outlet a of a compressor and enters an oil separator from an inlet m of the oil separator after passing through a first connecting copper pipe, the high-temperature high-pressure oil mist mixed refrigerant in the oil separator is subjected to oil mist separation, lubricating oil enters the bottom of the oil separator along the inner wall surface of the oil separator, the high-temperature high-pressure refrigerant gas is arranged at the upper part of the oil separator, the high-temperature high-pressure refrigerant gas flows out from an outlet n of the oil separator, lubricating oil at the bottom of the oil separator returns from an oil outlet f through an oil return capillary tube, the high-temperature high-pressure refrigerant gas from the oil separator enters an outdoor condenser for heat release and condensation, the condensed liquid refrigerant simultaneously flows through an electronic expansion valve and a one-way valve, and then the liquid refrigerant enters each indoor unit through a liquid stop valve, the electronic expansion valve throttles, the throttled refrigerant absorbs heat in the evaporator of each indoor unit to realize refrigeration of each indoor unit, the refrigerant flowing out of the indoor unit enters the inlet x of the gas-liquid separator through the gas stop valve to carry out gas-liquid separation, the separated low-temperature low-pressure refrigerant gas flows out of the outlet y of the gas-liquid separator to enter the inlet b of the compressor to be compressed by the compressor, a refrigeration cycle is realized, the normally closed gas bypass electromagnetic valve is electrically bypassed when the pressure difference of the multi-connected air conditioning system is large, thereby playing the role of balancing the pressure of the system, the oil return capillary tube returns the lubricating oil of the compressor in the oil separator from the oil outlet f of the oil separator in real time, the lubricating oil is sucked into the inlet b of the compressor to lubricate the compressor, and the bottom gas-liquid separation oil return hole in the gas-liquid separator sucks a small amount of refrigeration oil at the bottom of the gas-liquid separator to the compressor.

S2, improving efficiency: when the multi-split air conditioner outdoor unit is produced, the normally closed gas bypass electromagnetic valve is electrified, the oil separator and the gas-liquid separator are in a communicated state, at the moment, the compressor refrigeration oil is filled through the oil return needle valve interface, the compressor refrigeration oil enters the oil return needle valve and then is guided into the oil separator and the gas-liquid separator through the Y-shaped tee joint, the amount of the compressor refrigeration oil filled in the oil separator and the gas-liquid separator is equivalent, and the accuracy production efficiency of the compressor refrigeration oil filled in the oil separator and the gas-liquid separator is improved.

(III) advantageous effects

Compared with the prior art, the invention provides a method for rapidly filling cold oil in a multi-split air conditioner and a refrigerating system, and the method has the following beneficial effects:

the invention aims to improve a method for rapidly filling compressor refrigeration oil into an outdoor unit of a multi-split air conditioner, optimize a refrigeration system of the multi-split air conditioner, improve the efficiency of filling the refrigeration oil during the production of the multi-split air conditioner, ensure that oil is stored in an oil separator and gas-liquid separation, and provide guarantee for the stable operation of the multi-split air conditioner.

Drawings

FIG. 1 is a schematic view of a multiple refrigerant unit system according to the present invention;

fig. 2 is a schematic diagram of the structure of the frozen oil filling model of the invention.

In the figure: 1. a compressor; 101. an outlet a; 102. an inlet b; 21. a first connecting copper pipe; 22. a second connecting copper pipe; 23. a third connecting copper pipe; 24. a fourth connecting copper pipe; 25. a fifth connecting copper pipe; 26. a sixth connecting copper pipe; 27. a seventh connecting copper pipe; 3. an oil separator; 31. an inlet m; 32. an outlet n; 33. an oil outlet f; 4. an oil return capillary tube; 5. an oil return needle valve; 6. a Y-shaped tee joint; 7. a normally closed gas bypass solenoid valve; 8. an outdoor condenser; 9. an electronic expansion valve; 10. a one-way valve; 11. a liquid stop valve; 12. a gas shutoff valve; 13. a gas-liquid separator; 131. an inlet x; 132. an outlet y; 14. gas is divided into oil return holes; 15. an indoor unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, a method for rapidly filling cold oil in a multi-split air conditioner and a refrigeration system thereof include a compressor 1, wherein one end of the compressor 1 is fixedly connected with an outlet a101, one end of the outlet a101 is fixedly connected with an inlet m31 through a first connecting copper pipe 21, one end of the inlet m31 is fixedly connected with an oil separator 3, one end of the oil separator 3 is fixedly connected with an outlet n32, one end of the outlet n32 is fixedly connected with an outdoor condenser 8 through a fourth connecting copper pipe 24, one end of the outdoor condenser 8 is movably connected with a liquid stop valve 11 through a sixth connecting copper pipe 26, one end of the liquid stop valve 11 is fixedly connected with an indoor unit 15, one end of the sixth connecting copper pipe 26 is fixedly connected with a check valve 10, one end of the sixth connecting copper pipe 26 located at positions at the left and right ends of the check valve 10 is fixedly connected with a fifth connecting copper pipe 25, one end of the fifth connecting copper pipe 25 is fixedly connected with an electronic expansion valve 9, one end of the fourth connecting copper pipe 24 is fixedly connected with a seventh connecting copper pipe 27, one end of the seventh connecting copper pipe 27 is fixedly connected with a Y-shaped tee joint 6, one end of the Y-shaped tee joint 6 is fixedly connected with an oil return capillary valve 5, one end of the seventh connecting copper pipe 27 is fixedly connected with a normally-closed gas bypass electromagnetic valve 7, one end of the seventh connecting copper pipe 27 is fixedly connected with a third connecting copper pipe 23, one end of the third connecting copper pipe 23 is movably connected with a gas stop valve 12, one end of the gas stop valve 12 is fixedly connected with an indoor unit 15, one end of the third connecting copper pipe 23 is fixedly connected with an inlet x131, one end of the inlet x131 is fixedly connected with a gas-liquid separator 13, one end of the gas-liquid separator 13 is fixedly connected with an outlet Y132, one end of the outlet Y132 is fixedly connected with a second connecting copper pipe 22, and one end of the second connecting copper pipe 22 is fixedly connected with an inlet b102, the compressor 1 is fixedly connected to one end of the inlet b102, and the arrangement aims to improve the method for quickly filling the compressor refrigerant oil into the outdoor unit of the multi-split air conditioner, optimize the refrigeration system of the multi-split air conditioner, improve the efficiency of filling the refrigerant oil during the production of the multi-split air conditioner, ensure that oil is stored in the oil separator and the gas-liquid separation, and provide guarantee for the stable operation of the multi-split air conditioner.

Specifically, the first connecting copper pipe 21, the second connecting copper pipe 22, the third connecting copper pipe 23, the fourth connecting copper pipe 24, the fifth connecting copper pipe 25, the sixth connecting copper pipe 26, and the seventh connecting copper pipe 27 are connected to the refrigeration fitting by brazing, and this arrangement makes the connecting copper pipe and the refrigeration fitting connected by brazing, thereby increasing the connection stability of the connecting copper pipe and the refrigeration fitting.

Specifically, the third connecting copper pipe 23 and the sixth connecting copper pipe 26 are connected with the liquid stop valve 11 and the gas stop valve 12 through threads, and the liquid stop valve 11 and the gas stop valve 12 are detached from the third connecting copper pipe 23 and the sixth connecting copper pipe 26 conveniently, so that the liquid stop valve 11 and the gas stop valve 12 can be replaced conveniently.

Specifically, an air separation oil return hole 14 is formed in one end of the gas-liquid separator 13, and the arrangement enables the bottom air separation oil return hole 14 in the gas-liquid separator 13 to suck a small amount of refrigeration oil at the bottom of the gas-liquid separator 13 into the compressor 1.

Specifically, one end of the oil separator 3 is fixedly connected with an oil outlet f33, one end of the oil outlet f33 is fixedly connected with an oil return capillary tube 4, one end of the oil return capillary tube 4 is fixedly connected with a second connecting copper tube 22, the arrangement enables high-temperature and high-pressure refrigerant gas to flow out of an outlet n32 of the oil separator 3, and lubricating oil at the bottom of the oil separator 3 returns through the oil return capillary tube 4 from the oil outlet f 33.

A method for rapidly charging cold oil on-line and a use method of a refrigeration system, comprising the method for rapidly charging cold oil on-line and the refrigeration system as claimed in any one of claims 1 to 5, comprising the following steps:

s1, filling cold oil: in the refrigeration cycle during the outdoor unit refrigeration operation, when the multi-split air conditioner is at the outdoor side refrigeration working environment temperature, the refrigerant gas of the outdoor unit passes through the high-temperature and high-pressure oil mist mixed refrigerant gas discharged from the outlet a101 of the compressor 1, passes through the first connecting copper pipe 21 and then enters the oil separator 3 from the inlet m31 of the oil separator 3, the high-temperature and high-pressure oil mist mixed refrigerant in the oil separator 3 is subjected to oil mist separation, lubricating oil enters the bottom of the oil separator 3 along the inner wall surface of the oil separator 3, the high-temperature and high-pressure refrigerant gas is arranged at the upper part of the oil separator 3, the high-temperature and high-pressure refrigerant gas flows out from the outlet n32 of the oil separator 3, the lubricating oil at the bottom of the oil separator 3 returns from the oil outlet f33 through the oil return capillary tube 4, the high-temperature and high-pressure refrigerant gas from the oil separator 3 enters the outdoor condenser 8 for heat release and condensation, and the condensed liquid refrigerant simultaneously flows through the electronic expansion valve 9 and the one-way valve 10, then liquid refrigerant enters each indoor unit through a liquid stop valve 11, the electronic expansion valve 9 throttles, the throttled refrigerant absorbs heat in an evaporator in each indoor unit to realize refrigeration of each indoor unit, the refrigerant flowing out of each indoor unit enters an inlet x131 of a gas-liquid separator 13 through a gas stop valve 12 to be subjected to gas-liquid separation, the separated low-temperature low-pressure refrigerant gas flows out of an outlet y132 of the gas-liquid separator 13 to enter an inlet b102 of a compressor 1 to be compressed by the compressor 1 to realize a refrigeration cycle, a normally closed gas-bypass electromagnetic valve 7 is subjected to electric bypass when the high-low pressure difference of the multi-connected air conditioning system is large to play a role in balancing the system pressure, a lubricating oil of the compressor 1 in the oil separator 3 is returned from an oil outlet f33 of the oil separator 3 by an oil return capillary tube 4 in real time, the lubricating oil is sucked into the inlet b102 of the compressor 1 to lubricate the compressor 1, and a small amount of refrigerating oil at the bottom of the gas-liquid separator 13 is sucked into the compressor 1 by a bottom gas-liquid return hole 14 in the gas-liquid separator 13, the refrigeration cycle aims to realize a simple multi-split air conditioning refrigeration cycle.

S2, improving efficiency: when the multi-split air conditioner outdoor unit is produced, the normally closed gas bypass electromagnetic valve 7 is powered on, the oil separator 3 and the gas-liquid separator 13 are in a communicated state, at the moment, the compressor refrigeration oil is filled through the oil return capillary needle valve 5, the compressor refrigeration oil enters the oil return capillary needle valve 5 and then is simultaneously guided into the oil separator 3 and the gas-liquid separator 13 through the Y-shaped tee joint 6, the amount of the compressor refrigeration oil filled in the oil separator 3 and the gas-liquid separator 13 is equivalent, and the accuracy production efficiency of the filling of the compressor refrigeration oil is improved.

The working principle is as follows: in the refrigeration cycle during the outdoor unit refrigeration operation, when the multi-split air conditioner is at the outdoor side refrigeration working environment temperature, the refrigerant gas of the outdoor unit passes through the high-temperature and high-pressure oil mist mixed refrigerant gas discharged from the outlet a101 of the compressor 1, passes through the first connecting copper pipe 21 and then enters the oil separator 3 from the inlet m31 of the oil separator 3, the high-temperature and high-pressure oil mist mixed refrigerant in the oil separator 3 is subjected to oil mist separation, lubricating oil enters the bottom of the oil separator 3 along the inner wall surface of the oil separator 3, the high-temperature and high-pressure refrigerant gas is arranged at the upper part of the oil separator 3, the high-temperature and high-pressure refrigerant gas flows out from the outlet n32 of the oil separator 3, the lubricating oil at the bottom of the oil separator 3 returns from the oil outlet f33 through the oil return capillary tube 4, the high-temperature and high-pressure refrigerant gas from the oil separator 3 enters the outdoor condenser 8 for heat release and condensation, and the condensed liquid refrigerant simultaneously flows through the electronic expansion valve 9 and the one-way valve 10, then liquid refrigerant enters each indoor unit through a liquid stop valve 11, the electronic expansion valve 9 throttles, the throttled refrigerant absorbs heat in an evaporator in each indoor unit to realize refrigeration of each indoor unit, the refrigerant flowing out of each indoor unit enters an inlet x131 of a gas-liquid separator 13 through a gas stop valve 12 to be subjected to gas-liquid separation, the separated low-temperature low-pressure refrigerant gas flows out of an outlet y132 of the gas-liquid separator 13 to enter an inlet b102 of a compressor 1 to be compressed by the compressor 1 to realize a refrigeration cycle, a normally closed gas-bypass electromagnetic valve 7 is subjected to electric bypass when the high-low pressure difference of the multi-connected air conditioning system is large to play a role in balancing the system pressure, a lubricating oil of the compressor 1 in the oil separator 3 is returned from an oil outlet f33 of the oil separator 3 by an oil return capillary tube 4 in real time, the lubricating oil is sucked into the inlet b102 of the compressor 1 to lubricate the compressor 1, and a small amount of refrigerating oil at the bottom of the gas-liquid separator 13 is sucked into the compressor 1 by a bottom gas-liquid return hole 14 in the gas-liquid separator 13, the refrigeration cycle aims to realize simple multi-split air conditioner refrigeration cycle, when the multi-split air conditioner outdoor unit is produced, the normally closed air bypass electromagnetic valve 7 is electrified, the oil separator 3 and the air liquid separator 13 are in a communicated state, at the moment, the compressor refrigeration oil is filled through the oil return capillary needle valve 5, the compressor refrigeration oil is simultaneously guided into the oil separator 3 and the air liquid separator 13 through the Y-shaped tee joint 6 after entering the oil return capillary needle valve 5, the amount of the compressor refrigeration oil filled in the oil separator 3 and the air liquid separator 13 is equal, and the accuracy production efficiency of the compressor refrigeration oil filling is improved.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.