KR20050065258A - A oil balancing method of multiple compressor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fungal oil method capable of appropriately restoring the amount of compressor oil by preventing the inflow of refrigerant gas into the fungal oil pipe, wherein the first to third compressors 11 to 13 and the first to third compressors ( 11 to 13 to supply oil, and is connected to the bacteria oil pipe 16 and the first to third compressors 11 to 13 connected to each other through the milk oil pipe assembly point P3 to the first to third compressors 11. Chemical oil which performs the fuel oil of each container 11a, 12a, 13a of the 1st-3rd compressors 11-13 with respect to the refrigerant circuit Ka provided with the suction pipe 14 which supplies refrigerant gas to ~ 13. The method is characterized by equalizing the pressure during operation in the compressor vessel other than the compressor for performing the homogenizing with the pressure of the homogenizing pipe collecting point P3.

Description

A oil balancing method of multiple compressors

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication method of a plurality of compressors capable of appropriately maintaining each compressor oil amount in a plurality of compressors that can be used in an air conditioner or the like.

An example of an air conditioner is a so-called multi-type air conditioner having a plurality of compressors in one outdoor unit so as to cope with a plurality of indoor units.

In the case of such an air conditioner, when the oil is stored for a long time, the amount of oil stored by each compressor is changed, and thus, the compressor may be damaged due to a lack of oil. In the event that a deviation occurs in the compressor oil amount due to a long time operation, a milk oil system has been proposed in which excess oil of each compressor is sequentially moved through a milk oil pipe to return oil to an appropriate amount (Japanese Patent Application Laid-Open No. 10-205897). (See Figure 1)).

Referring to the fuel oil system of the plurality of compressors described in the above publication briefly, as shown in FIG. 3, the suction pipes as suction side refrigerant pipes such that the three compressors 51, 52, and 53 are parallel to each other in the refrigerant circuit Kb ( 54) and a discharge pipe 55 which is a discharge side refrigerant pipe, respectively. The vessels 51a, 52a, 53a of the compressors are in communication with each other via the milk oil tube 56. The discharge pipes 55 of the compressors 51, 52, 53 are connected to the fungal oil pipe 56 by a bypass pipe 58 in which an on-off valve 57 is provided halfway.

Such a fungal oil system opens the on / off valve 57 and introduces the high pressure refrigerant gas into the fungal oil pipe 56 through the bypass pipe 58 during the normal cooling and heating operation. This prevents the movement of the oil mist between the compressor vessels 51a, 52a, and 53a through the fungal oil pipe 56, thereby preventing the shortage of oil generated in the high pressure side compressor.

In addition, when the oil amount between the vessels 51a, 52a, 53a of each compressor is changed by the long time operation, the compressors 51, 52, 53 are operated sequentially one by one with the closing valve 57 closed. By performing so-called fungal oil operation, the excess oil of each compressor (51, 52, 53) is sequentially moved through the fungal oil pipe (56) to return the amount of oil in the containers (51a, 52a, 53a) of each compressor to an appropriate value. I'm trying to.

On the other hand, the diameter of the bypass pipe 58 is much smaller than the diameter of the fungal oil pipe 56, so that liquid oil cannot move between the compressors through the small diameter bypass pipe 58.

However, the following problems still remain in the conventional fungal oil system described above. That is, when only the compressor 51 is operated, for example, as shown in FIG. 3, for the oil fuel operation in which a plurality of compressors are operated one by one, when the oil level of the compressor 52 becomes lower than the oil fuel pipe connection port 52b, the compressor. The refrigerant gas flowing from the suction pipe 54 connected to the 51 flows out into the fungal oil pipe 56 (see the white arrow in FIG. 3). Here, since the viscosity of the refrigerant gas is lower than that of the oil, the oil flowing out from the compressor 53 to the fungal oil pipe 56 does not easily move to the compressor 51. Therefore, there is a possibility that the oil amount cannot be returned to an appropriate value even if the oil oil operation is performed.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a fungal oil method capable of appropriately restoring the amount of compressor oil by preventing the inflow of refrigerant gas into the fungal oil pipe.

MEANS TO SOLVE THE PROBLEM This invention employ | adopted the following structures in order to solve the said subject. In other words, the fuel oil method of the present invention supplies oil to three or more compressors, the plurality of compressors, and the fuel oil pipes connected to each other via the fuel oil pipe branching point, and the refrigerant gas to the compressors. In the fuel oil method for performing fuel oil in each of the containers of the plurality of compressors to the refrigerant circuit having a suction pipe, the pressure during operation in the container of the compressor other than the compressor that performs the fuel oil and the pressure of the fluid oil pipe assembly point Characterized in that the same.

In the fuel oil method according to the present invention, by equalizing the pressure in the compressor vessel other than the object to be used with the oil and the pressure at the point where the oil is collected, the refrigerant gas is prevented from flowing from the compressor other than the object to be used as the oil to the milk oil tube. Only oil will flow. Therefore, it is possible to reliably and quickly return each compressor oil amount to an appropriate value.

In addition, the milk oil method according to the present invention includes a low pressure vessel type first compressor, a second compressor, and a third compressor connected in parallel to each other, a milk oil pipe branched at a milk oil pipe assembly point and connected to each container of the compressors, A suction side refrigerant pipe connected to each container of the compressors is provided, and the refrigerant pipe on the suction side is branched at the first suction pipe branch point and connected to the second compressor, and at the first suction pipe branch point. A second branch suction pipe branched from the first branch suction pipe, the second branch suction pipe branched from a second suction pipe branch point, connected to the first compressor, and branched from the second suction pipe branch point; And a fourth branch suction pipe connected to the third compressor, wherein the pipe pressure loss of the third branch suction pipe and the third compressor and the same oil filling pipe assembly point of the oil filling pipe Equal to the pipe pressure loss, the pipe pressure loss of the fourth branch suction pipe is equal to the pipe pressure loss between the first compressor and the fungus pipe assembly point of the fungus pipe, and the pipe pressure loss of the second branch suction pipe And a fuel oil method for performing fuel oil in each of the containers of the first compressor, the second compressor, and the third compressor with respect to the refrigerant circuit having the same pipe pressure loss between the second compressor and the oil fuel pipe assembly point of the fuel oil pipe. A first process of stopping the first compressor, operating the second compressor and the third compressor, and a second process of stopping the first compressor and the second compressor, and operating the third compressor. And a third step of driving the first compressor and the second compressor and stopping the third compressor, and a fourth step of driving the first compressor and stopping the second compressor and the third compressor. , Prize The process of claim 1, wherein the second process, the third step, and characterized in that for performing the fourth step in any order.

In the fuel oil method according to the present invention, when the first compressor is stopped and the second compressor and the third compressor are operated, the oil level of the third compressor is equal to the third pressure by equalizing the pressure in the vessel of the third compressor and the pressure of the homogeneous pipe assembly point. Even when it is lower than the connection port of the fluid oil pipe connected to the compressor, it is possible to prevent the refrigerant gas from flowing out from the third compressor to the fluid oil pipe. Therefore, the oil is moved through the bacteria oil pipe from the first compressor in the stationary state to the second compressor in the operation state, so that the oil is made.

In addition, when the first compressor and the second compressor are stopped and the third compressor is operated, the pressure in the vessel of the first compressor and the pressure at the homogeneous conduit point are the same. This moves and the milk is made.

In addition, when the first compressor and the second compressor are operated and the third compressor is stopped, the pressure in the vessel of the first compressor and the pressure at the homogeneous conduit are equal to each other. This moves and the milk is made.

When the first compressor is operated, and the second compressor and the third compressor are stopped, the pressure in the vessel of the third compressor and the pressure at the homogeneous conduit point are the same, so that the pressure from the second compressor to the first compressor is as described above. The oil is moved to make fungus.

In this way, the pressure in the vessel of the compressor other than the object to carry out the oil is equal to the pressure of the assembly point of the milk oil pipe, so that the refrigerant gas is not leaked from the compressor except the object to the oil to the milk oil pipe, so that only oil is used as the milk oil pipe. Will pass. Therefore, it is possible to reliably and quickly return each compressor oil amount to an appropriate value.

Hereinafter, an embodiment of the fungal oil system according to the present invention will be described with reference to FIG. 1.

The fungal oil system according to the present embodiment can be used in a refrigerant circuit such as an air conditioner.

As shown in FIG. 1, the refrigerant circuit Ka includes the suction pipe 14 and the discharge side of the suction side refrigerant pipe such that the first compressor 11, the second compressor 12, and the third compressor 13 are parallel to each other. It is connected to the discharge pipe 15 which is a refrigerant pipe, respectively. The vessels 11a, 12a, 13a of the first compressor 11, the second compressor 12, and the third compressor 13 are in communication with each other via the oil milk tube 16. In addition, the 1st compressor 11, the 2nd compressor 12, and the 3rd compressor 13 which are used here are low pressure container type compressors.

The suction pipe 14 branches from the main suction pipe 21 common to the first to third compressors 11, 12, and 13 and the first suction pipe branch point P1 to connect the main suction pipe 21 and the second compressor. The 1st branch suction pipe 22 and the 2nd branch suction pipe 23 branched with the 1st branch suction pipe 22 in the 1st suction pipe branch point P1 are provided. In addition, the second branch suction pipe 23 is branched from the second suction pipe branch point P2 to the third branch suction pipe 24 connected to the first compressor 11, and the fourth branch suction pipe connected to the third compressor 13. (25) is provided.

The fungal oil conduit 16 includes the first branch oil condensed conduit 31, the fungal milk conduit assembly point P3 and the second connecting the fungal milk conduit assembly point P3 and the fungal milk conduit connection port 11b of the first compressor 11. 2nd branch which connects the oil-filling pipe connection part 12b of the compressor 12, 3rd branch which connects the oil-filling pipe assembly point P3 and the oil-filling pipe connection port 13b of the 3rd compressor 13. A fungal oil tube 33 is provided.

Here, the third branch suction pipe ₂₄ and the third branch funnel pipe ₃₃ have the same pipe pressure loss Δ ₂₄ of the third branch suction pipe ₂₄ and the pipe pressure loss Δ ₃₃ of the third branch funnel pipe 33. The fourth branch suction pipe 25 and the first branch fuel oil pipe 31 each have a shape that can be cut, and the pipe pressures of the pipe pressure drop Δ ₂₅ and the first branch fuel oil pipe 31 of the fourth branch suction pipe 25 are reduced. Loss Δ ₃₁ has a shape that can be equal to each other, and the second branch suction pipe 23 and the second branch fuel oil pipe 32 are the pipe pressure loss Δ ₂₃ and the second branch fuel oil pipe of the second branch suction pipe 23. each has a shape that a pressure loss in piping of the Δ ₃₂ (32) can be the same.

Subsequently, the method of oiling of the refrigerant circuit Ka configured as described above will be described with reference to FIG. 2.

First, only the first compressor 11 is stopped and the second compressor 12 and the third compressor 13 are in an operating state (step ST1). Here, since the first compressor 11 is stopped, no pipe pressure loss occurs in the third branch suction pipe 24, so that the pressure at the second suction pipe branch point P2 and the pressure in the container 11a of the first compressor 11 are reduced. Becomes the same. In addition, since the pipe pressure loss Δ ₂₅ of the fourth branch suction pipe 25 and the pipe pressure loss Δ ₃₁ of the first branch bacterial oil pipe ₃₁ are equal to each other, the pressure at the milking pipe assembly point P3 and the third The pressure in the container 13a of the compressor 13 becomes equal. Therefore, even when the oil level of the third compressor 13 other than the milking oil object is lower than the milking oil pipe connection opening 13b, the refrigerant gas is prevented from flowing from the third compressor 13 to the milking oil pipe 16 so that the first compressor ( From 11) between the second compressor 12, the oil is made.

Next, the first compressor 11 and the second compressor 12 are stopped and only the third compressor 13 is operated (step ST2). Here, as the first compressor 11 is stopped, the pressure at the second suction pipe branch point P2 and the pressure in the container 11a of the first compressor 11 become equal for the same reason as described above. Moreover, the pressure in the 1st suction pipe branch point P1 and the pressure in the container 12a of the 2nd compressor 12 become equal. In addition, since the pipe pressure loss Δ ₂₃ of the second branch suction pipe 23 and the pipe pressure loss Δ ₃₂ of the second branch bacterial oil pipe ₃₂ are equal to each other, the pressure at the milking pipe collection point P3 and the first The pressure in the container 11a of the compressor 11 becomes equal. Therefore, as described above, the refrigerant gas is prevented from flowing into the bacteria oil pipe 16 from the first compressor 11, so that the bacteria oil is formed between the second compressor 12 and the third compressor 13.

Then, the first compressor 11 and the second compressor 12 are operated to stop only the third compressor 13 (step ST3). Here, as the third compressor 13 is stopped, the pressure at the second suction pipe branch point P2 is equal to the pressure in the third compressor 13 container 13a for the same reason as described above. In addition, since the pipe pressure loss Δ ₂₄ of the third branch suction pipe ₂₄ and the pipe pressure loss Δ ₃₃ of the third branch bacterial oil pipe ₃₃ are equal to each other, the pressure at the milking pipe assembly point P3 and the first The pressure in the container 11a of the compressor 11 becomes equal. Accordingly, as described above, the refrigerant gas is prevented from flowing into the bacteria oil pipe 16 from the first compressor 11, so that the bacteria oil is formed between the third compressor 13 and the second compressor 12.

Finally, only the first compressor 11 is operated to stop the second compressor 12 and the third compressor 13 (step ST4). Here, the pressure at the 2nd suction pipe branch point P2 and the pressure in the container 13a of the 3rd compressor 13 become equal for the reason mentioned above. Moreover, the pressure in the 1st suction pipe branch point P1 and the pressure in the container 12a of the 2nd compressor 12 become equal. In addition, since the pipe pressure loss Δ ₂₃ of the second branch suction pipe 23 and the pipe pressure loss Δ ₃₂ of the second branch bacterial oil pipe ₃₂ are equal to each other, the pressure at the milking pipe assembly point P3 and the third The pressure in the container 13a of the compressor 13 becomes equal. Therefore, as described above, the refrigerant gas is prevented from flowing into the bacteria oil pipe 16 from the third compressor 13, so that the bacteria oil is formed between the second compressor 12 and the first compressor 11.

By the above, the oil inside each container 11a, 12a, 13a in the 1st compressor 11, the 2nd compressor 12, and the 3rd compressor 13 is performed.

According to the milking system and the milking method configured as described above, the milking pipe 16 and the suction pipe 14 are the pipe pressure loss of the pipe pressure loss of the third branch suction pipe ₂₄ and Δ ₂₄ and the third branch fuel oil pipe 33. Δ ₃₃ is the same, Δ 25 which is the pipe pressure loss of the fourth branch suction pipe ₂₅ and Δ 31 which is the pipe pressure loss of the first branch fuel oil pipe ₃₁ are the same, and Δ which is the pipe pressure loss of the second branch suction pipe 23. _Since the pipe pressure loss Δ ₃₂ of the ₂₃ and the second branch fuel oil pipe ₃₂ has the same shape as that of the compressor, the pressure of the compressor other than the fuel oil object and the pressure of the fluid oil pipe assembly point P3 in the process become the same. As a result, oil is prevented from flowing out of the compressor other than the fuel oil object to the bacteria oil pipe 16, and only oil is moved to the bacteria oil pipe 16. Therefore, it is possible to reliably and quickly return each compressor oil amount to an appropriate value.

In addition, since two compressors of the first compressor 11, the second compressor 12, and the third compressor 13 are operated in the first process and the third process, the amount of deterioration of the cooling capacity is suppressed when the oil-based operation is performed. .

In addition, the first compressor 11, the second compressor 12, the third compressor 13, and the same oil soaking point P3 so that the refrigerant gas does not flow out from the compressor other than the object for performing the oil soaking into the oil milk tube 16. Since there is no need to provide an on-off valve between them, it can shorten the time to carry out the operation of fuel oil and also prevent the compressor failure due to the malfunction of the on-off valve or the clogging of unnecessary things such as garbage in the on-off valve, thereby improving the reliability of the fuel oil system. Can be improved.

In addition, this invention is not limited to said embodiment, It is possible to add various changes in the range which does not deviate from the meaning of this invention.

For example, in the above-described embodiment, the oil-fuel method can also be performed in any order from the first step to the fourth step.

In addition, although the above-mentioned embodiment showed the method of equalizing oil of three compressors, the present invention is not limited thereto, and four or more types are possible as long as the pressure in the compressor vessel and the pressure of the same level of branching pipes are the same when the compressors other than the oil-containing object are operated.

According to the fuel oil method and fuel oil system of the present invention, even when the oil level of the compressor is lower than that of the fuel oil pipe connection by equalizing the pressure in the compressor vessel other than the object to which the oil is to be carried out and the pressure of the fuel oil pipe assembly point, the fuel oil pipe from the compressor This can prevent the refrigerant gas from flowing out. Therefore, only the oil flows in the fluid oil pipe between the compressors performing the oil, and the oil amount of each compressor can be returned to the proper value reliably and quickly.

1 is a schematic side cross-sectional view showing a fuel oil system of a plurality of compressors in one embodiment according to the present invention,

Fig. 2 is a flowchart showing the fungal milk method in one embodiment according to the present invention.

3 is a schematic side cross-sectional view showing a homogeneous oil system of a plurality of conventional compressors.

*** Explanation of symbols for main parts of drawing ***

11 first compressor

12 second compressor

13 third compressor

11a, 12a, 13a container

16 fungal ducts

14 suction line

21st branch suction line

23 2nd branch suction line

24 3rd branch suction line

25 4th quarter suction line

Ka refrigerant circuit

P1 1st suction branching point

P2 2nd suction line junction

P3 fungal duct assembly point

Claims (2)

A refrigerant circuit comprising three or more compressors, a fuel oil pipe which supplies oil to the plurality of compressors and is connected to each other through a fuel oil pipe branching point, and a suction pipe connected to the plurality of compressors to supply refrigerant gas to the compressor. In the fuel oil method for performing the fuel oil of each container of the plurality of compressors, The method of claim 1, wherein the pressure during operation in the compressor vessel other than the compressor for performing the lubricating oil is equal to the pressure of the assembly point of the lubricating oil pipe. A low pressure vessel type first compressor, second compressor, and third compressor connected in parallel with each other, A fungal milk pipe branched at the fungal milk pipe assembly point and connected to each container of each compressor; A suction side refrigerant pipe connected to each container of each of the compressors is provided, The suction side refrigerant pipe branched from the first suction pipe branch point and connected to the second compressor, and a second branch suction pipe branched from the first suction pipe branch point to the first branch suction pipe, A second branch suction pipe branched from the second suction pipe branch point and connected to the first compressor, and a fourth branch suction pipe branched from the second suction tube branch point and connected to the third compressor, The pipe pressure loss of the third branch suction pipe is equal to the pipe pressure loss between the third compressor and the fungus pipe assembly point of the fungus pipe, The pipe pressure loss of the fourth branch suction pipe is equal to the pipe pressure loss between the first compressor and the fungus pipe assembly point of the fungus pipe, For the refrigerant circuit in which the pipe pressure loss of the second branch suction pipe and the pipe pressure loss between the second compressor and the milk oil pipe assembly point of the milk oil pipe are equal, the first compressor, the second compressor, and the third compressor In the fungal oil method for performing the fungal oil of each container, A first step of stopping the first compressor and operating the second compressor and the third compressor; A second step of stopping the first compressor and the second compressor and operating the third compressor; A third step of driving the first compressor and the second compressor to stop the third compressor; A fourth step of operating the first compressor and stopping the second compressor and the third compressor, The first step, the second step, the third step and the fourth step is a fungal method, characterized in that to perform in any order.