JP2015155772A - oil separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve separation characteristics of a refrigerating machine oil when introducing the refrigerating machine oil into a shell so as to be deviated to an outer peripheral side of an inlet pipe.

SOLUTION: An oil separator 100 includes: an inlet pipe 15 having a bent pipe part 15a on an upstream side, connected to a shell 11 on a downstream side and allowing a refrigerant in which a refrigerating machine oil is mixed to flow into the shell 11; and a cylindrical member 12 provided in the shell 11 and being coaxial with a central axis of the shell 11. The inside of the inlet pipe 15 is separated into a first inlet part 15b and a second inlet part 15c at a connection portion with the shell 11. The first inlet part 15b opens to a first space 20, and the second inlet part 15c opens to a second space 21.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to an oil separator that separates refrigerating machine oil from a gas-phase refrigerant mixed with refrigerating machine oil.

  Generally, refrigeration oil is used for lubrication of a compressor used in an air conditioner or the like. This refrigerating machine oil circulates in a refrigerant circulation system together with a gas phase refrigerant (hereinafter referred to as a refrigerant). The refrigerating machine oil sucked from the suction side of the compressor is supplied to each sliding portion inside the compressor and used for lubrication of each sliding portion. In addition, the refrigerating machine oil is supplied to the working chamber of the compressor and is used to prevent the leakage of the vaporized refrigerant by sealing the gap in the working chamber.

  In the above circulation system, when the refrigerant discharged from the compressor contains a large amount of refrigerating machine oil, the refrigerating machine oil tends to adhere to the inner wall surface of the heat transfer tube of the heat exchanger. And the refrigeration oil adhering to the inner wall face of a heat exchanger tube inhibits the heat transfer of a heat exchanger tube, and deteriorates the heat transfer efficiency of a heat exchanger. In order to avoid such a situation, an oil separator is provided in the circulation system.

  FIG. 1 is a diagram illustrating a configuration example of a conventional oil separator 10 disclosed in Patent Document 1. In FIG. FIG. 1A is a top view of the oil separator 10, and FIG. 1B is a cross-sectional view of the oil separator 10. The oil separator 10 includes a shell 1, a cylindrical member 2, an upper end plate 3, a lower end plate 4, an inlet pipe 5, an outlet pipe 6, and an oil return pipe 7. The inlet pipe 5 has a curved pipe part 5a. The arrows shown in FIGS. 1A and 1B indicate the direction in which the refrigerant flows.

  Refrigerating machine oil and refrigerant introduced into the shell 1 from the inlet pipe 5 are discharged into the shell 1 and descend while swirling. When the refrigerating machine oil flows into the shell 1 from the inlet pipe 5, oil drops of various sizes are scattered in the space between the cylindrical member 2 and the inner wall of the shell 1. The scattered oil droplets move to the outside of the shell 1 due to centrifugal force acting when turning, adhere to the inner wall of the shell 1, and are separated from the refrigerant. The oil droplets adhering to the inner wall of the shell 1 move downward by its own weight and are collected at the lower part of the oil separator 10. On the other hand, when the refrigerant reaches the lower end of the cylindrical member 2, the refrigerant flows into the cylindrical member 2 and is sent out from the outlet pipe 6.

  In this oil separator 10, a lot of refrigerating machine oil is biased from the inner peripheral side of the curved pipe part 5a to the inner wall on the outer peripheral side by the centrifugal force acting when passing through the curved pipe part 5a, thereby forming an oil film. Thereby, the refrigerating machine oil which flows through the inner wall on the inner peripheral side at the connection portion between the shell 1 and the inlet pipe 5 is reduced. Therefore, in the oil separator 10, it is possible to suppress the generation of oil droplets having a small diameter that floats in the vicinity of the outlet pipe 6 and is delivered from the outlet pipe 6 without being separated from the refrigerant. As a result, the oil separator 10 can improve the separation characteristics of the refrigerating machine oil.

JP 2010-286193 A

  However, in the oil separator 10 of Patent Document 1, not all of the refrigerating machine oil contained in the refrigerant forms an oil film on the inner wall on the outer peripheral side of the curved pipe portion 5a. That is, there is also a refrigerant that flows through the inner peripheral side of the inlet pipe 5 and is introduced into the shell 1. This refrigerant swirls in the shell 1 at a position away from the inner wall (near the center of the shell 1) and travels toward the outlet pipe 6 without colliding with the inner wall. Therefore, the refrigeration oil contained in the refrigerant drifts in the vicinity of the outlet pipe 6 and is sent out from the outlet pipe 6 without being separated from the refrigerant. Thereby, the isolation | separation characteristic (oil separation rate) of refrigeration oil falls.

  The object of the present invention is to separate the refrigerating machine oil introduced into the shell from the inner peripheral side of the inlet pipe from the refrigerant when the refrigerating machine oil is biased toward the outer peripheral side of the inlet pipe and introduced into the shell. It is to further improve the separation characteristics of machine oil.

  An oil separator according to an aspect of the present invention includes a cylindrical container and a curved pipe portion on the upstream side, connected to the container on the downstream side, and a refrigerant mixed with refrigerating machine oil. An inlet pipe that flows into the container through the outlet, an outlet pipe that is connected to the container and that flows out the refrigerant from which the refrigerating machine oil is separated, and is provided inside the container. A cylindrical member having a shape in which the central axis coincides with the central axis, the upper end is attached to the upper part of the container, and the lower end is opened to the lower space of the container, and the inside of the inlet pipe is connected to the container And a dividing member that is divided into a first inlet portion and a second inlet portion, wherein the first inlet portion opens into a first space that is a space between the inner wall of the container and the outer wall of the cylindrical member. The second inlet portion is formed in a second space that is a space inside the cylindrical member. A configuration that is mouth.

  The present invention can further improve the separation characteristics of refrigerating machine oil.

The top view which shows an example of a structure of the conventional oil separator which concerns on patent document 1 Sectional drawing which shows an example of a structure of the oil separator which concerns on patent document 1 Sectional drawing which shows an example of a structure of the oil separator which concerns on embodiment of this invention Sectional drawing which shows an example of a structure of the oil separator which concerns on embodiment of this invention The graph which shows the comparative example of the oil separation rate of the conventional oil separator and the oil separator which concerns on embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example, and the present invention is not limited to this embodiment.

  The configuration of the oil separator according to the embodiment of the present invention will be described below with reference to FIGS. 2 and 3. 2 and 3 are sectional views showing an example of the configuration of the oil separator 100 according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of the oil separator 100 cut along A-A ′ in FIG. 3. FIG. 3 is a cross-sectional view of the oil separator 100 taken along a plane that passes through the central axis of the shell 11 and is perpendicular to the central axis.

  In FIG. 2, the oil separator 100 includes a shell 11, a cylindrical member 12, an upper end plate 13, a lower end plate 14, an inlet pipe 15, an outlet pipe 16, and an oil return pipe 17.

  The shell 11 is a cylindrical container, and has an upper end plate 13 at an upper portion and a lower end plate 14 at a lower portion.

  The cylindrical member 12 is a cylindrical member whose upper and lower ends are open. The central axis of the cylindrical member 12 coincides with the central axis of the shell 11. As shown in FIG. 2, the cylindrical member 12 is provided inside the shell 11. The upper end of the cylindrical member 12 is attached to the upper end plate 13. On the other hand, the lower end of the cylindrical member 12 opens into the lower space of the shell 11.

  The inlet pipe 15 is connected to the side surface of the shell 11. The inlet pipe 15 allows the refrigeration oil and the refrigerant to flow into the shell 11 and the cylindrical member 12. The arrows shown in FIG. 2 indicate the inflow direction of the refrigerant. The detailed configuration of the inlet pipe 15 will be described later with reference to FIG.

  The outlet pipe 16 is connected to the upper end plate 13. The outlet pipe 16 allows the refrigerant from which the refrigeration oil is separated to flow out of the shell 11.

  The oil return pipe 17 is connected to the lower end plate 14. The oil return pipe 17 causes the refrigeration oil separated from the refrigerant and accumulated in the lower part of the shell 11 to flow out of the shell 11. This refrigerating machine oil is returned to the suction side of a compressor (not shown), for example. In addition, since the refrigerant | coolant discharged from a compressor is high temperature, when the refrigerating machine oil isolate | separated from the refrigerant | coolant is high temperature, it is good also as returning directly to the high temperature oil sump in the airtight container of a compressor. Further, the refrigerating machine oil separated from the refrigerant may be returned to the accumulator connected to the suction side of the compressor and cooled. In this way, the compressor can be operated more efficiently.

  As shown in FIG. 3, the inlet pipe 15 has a curved pipe portion 15 a on the upstream side, and is connected to the shell 11 on the downstream side. As shown in FIGS. 2 and 3, the inlet portion 15 has a first inlet portion 15 b and a second inlet portion 15 c at the connection portion with the shell 11. In FIG. 3, the arrow shown on the upstream side of the inlet pipe 15 indicates the inflow direction of the refrigerant.

  The curved pipe portion 15a has the same function and effect as the curved pipe portion of Patent Document 1. That is, a lot of refrigerating machine oil is biased to the inner wall on the outer peripheral side of the curved pipe portion 15a by the centrifugal force acting when passing through the curved pipe portion 15a, and forms an oil film.

  The first inlet portion 15 b is an opening on the outer peripheral side of the inlet pipe 15 in the space of the inlet pipe 15 divided into two by the dividing member 19. The first inlet portion 15 b is open to the first space 20. The first space 20 is a space between the inner wall of the shell 11 and the outer wall of the cylindrical member 12.

  Further, the tangent line on the outer peripheral side of the first inlet portion 15 b coincides with the tangent line of the inner wall of the shell 11. Thereby, the oil film flowing into the first space 20 can smoothly travel through the inner wall of the shell 11 from the inner wall on the outer peripheral side of the inlet pipe 15 (first inlet portion 15b). Further, the refrigerant flowing into the first space 20 can smoothly form a swirling flow along the inner wall of the shell 11. The details of the oil film and the refrigerant flow will be described later.

  The second inlet portion 15 c is an opening on the inner peripheral side of the inlet pipe 15 in the space of the inlet pipe 15 divided into two by the dividing member 19. The second inlet portion 15 c opens into the second space 21. The second space 21 is a space inside the cylindrical member 12. The second space 21 is farther from the inner wall of the shell 11 than the first space 20.

  Further, the tangent line on the outer peripheral side of the second inlet portion 15 c matches the tangent line of the inner wall of the cylindrical member 12. Thereby, the refrigerant flowing into the second space 20 can smoothly form a swirling flow along the inner wall of the cylindrical member 12. The details of the refrigerant flow will be described later.

  The coincidence between the tangent line on the outer peripheral side of the first inlet portion 15b and the tangent line on the inner wall of the shell 11, and the coincidence between the tangent line on the outer peripheral side of the second inlet portion 15c and the tangent line on the inner wall of the cylindrical member 12, respectively. It also includes the general agreement that the refrigerating machine oil flowing through the inlet pipe 15 smoothly flows into the inner wall of the shell 11 and the inner wall of the cylindrical member 12 without scattering.

  The dividing member 19 is disposed in the inner space of the inlet pipe 15 at the connection portion between the inlet pipe 15 and the shell 11 in order to divide the inner space of the inlet pipe 15 into the first inlet portion 15b and the second inlet portion 15c. It is a member (for example, plate-shaped member). In the example of FIG. 3, the dividing member 19 is a member in which a part of the cylindrical member 12 extends into the internal space of the inlet pipe 15.

  The dividing member 19 may be disposed on the central axis of the inlet pipe 15. In this case, the maximum width portion d1 of the first inlet portion 15b and the maximum width portion d2 of the second inlet portion 15c are the same. Alternatively, the dividing member 19 may be disposed near the outer peripheral side of the inlet portion 15b. In this case, the maximum width portion d1 of the first inlet portion 15b is smaller than the maximum width portion d2 of the second inlet portion 15c. Alternatively, the dividing member 19 may be disposed closer to the inner peripheral side of the inlet portion 15b. In this case, the maximum width portion d1 of the first inlet portion 15b is larger than the maximum width portion d2 of the second inlet portion 15c. Depending on the ratio of the maximum width portion d1 of the first inlet portion 15b and the maximum width portion d2 of the second inlet portion 15c, the oil separation rate will be different. This will be described later with reference to FIG.

  Regardless of the maximum width portions d1 and d2, the cross-sectional area of the first inlet portion 15b and the cross-sectional area of the second inlet portion 15c in FIG. In this case, the oil separation rate is most efficient (see FIG. 4).

  Next, the flow of refrigerating machine oil and refrigerant in the oil separator 100 will be described with reference to FIGS. 2 and 3.

  The refrigerating machine oil separated from the refrigerant by passing through the curved pipe portion 15a becomes an oil film, flows along the outer peripheral side of the inlet pipe 15, and flows into the first space 20 through the first inlet portion 15b. The refrigerating machine oil (oil film) that has flowed into the first space 20 travels down along the inner wall of the shell 11 due to its own weight, and accumulates in the lower portion of the shell 11.

  On the other hand, the refrigerating machine oil that has not been separated from the refrigerant by passing through the curved pipe portion 15a flows into the first space 20 and the second space 21 through the first inlet portion 15b or the second inlet portion 15c while being contained in the refrigerant. To do.

  The refrigerant flowing into the first space 20 becomes a swirl flow along the inner wall of the shell 11 in the first space 20 and descends while swirling. The refrigerating machine oil contained in the refrigerant is scattered as oil droplets of various sizes when flowing into the first space 20 from the first inlet 15b. The scattered oil droplets move toward the inner wall of the shell 11 and adhere to the inner wall of the shell 11 due to centrifugal force acting when turning. Thereby, refrigeration oil is isolate | separated from a refrigerant | coolant. Then, the refrigerating machine oil moves down along the inner wall of the shell 11 due to its own weight, and accumulates in the lower part of the shell 11.

  The refrigerant flowing into the second space 21 becomes a swirling flow along the inner wall of the cylindrical member 12 in the second space 21, and descends while swirling. The refrigerating machine oil contained in the refrigerant is scattered as oil droplets of various sizes when flowing into the second space 21 from the second inlet 15c. The oil droplet 18 shown in FIG. 3 is an example of the scattered oil droplet. The scattered oil droplets move toward the inner wall of the cylindrical member 12 and adhere to the inner wall of the cylindrical member 12 by centrifugal force acting when turning. Thereby, refrigeration oil is isolate | separated from a refrigerant | coolant. The refrigerating machine oil travels down along the inner wall of the cylindrical member 12 due to its own weight, and accumulates in the lower part of the shell 11.

  That is, the movement distance of the oil droplet 18 in the oil separator 100 of the present embodiment is the maximum width portion d2, and the oil droplet 18 in the oil separator (for example, the oil separator 10 of Patent Document 1) without the cylindrical member 12 is used. Is shorter than the moving distance d3 (d1 + d2 + thickness of the dividing member 19). In the case of the conventional oil separator, the oil droplet 18 at the position shown in FIG. 3 has a long moving distance d3 and may not reach the inner wall of the shell 11 and may drift in the space. In contrast, in the case of the oil separator 100 of the present embodiment, the oil droplet 18 at the position shown in FIG. 3 can easily reach the inner wall of the cylindrical member 12 because the maximum width portion d2 that is the movement distance is short.

  The refrigerant that has flowed into the first space 20 and the refrigerant that has flowed into the second space 21 descend in each space while swirling, reverse when they reach the bottom of the shell 11, and swirl in the second space 21. Then, it rises and is sent out from the outlet pipe 16.

  Next, the relationship between the oil separation rate of the oil separator 100 of the present embodiment and the ratio d2 / d3 will be described. FIG. 4 is a graph showing the relationship between the oil separation rate (vertical axis) and the ratio d2 / d3 (horizontal axis). The oil separation rate shown in FIG. 4 is a value obtained by a simulation using the Monte Carlo method, modeling the movement of oil droplets moving in the refrigerant in the radial direction of the shell 11 by centrifugal force. In this simulation, the thickness of the dividing member 19 is not considered.

  As shown in FIG. 4, when the oil separation rate of the conventional configuration (the configuration in which the cylindrical member 12 is not provided and the dividing member 19 is not provided in the inlet pipe 15) is 1, the configuration of the oil separator 100 (the cylindrical member 12 is The oil separation rate of the configuration in which the dividing member 19 is provided in the inlet pipe 15) is greater than 1, regardless of the ratio d2 / d3. In particular, when the ratio d2 / d3 = 0.5, the oil separation rate was the best. Therefore, in the oil separator 100 of the present embodiment, it is preferable that the maximum width portion d1 of the first inlet portion 15b is equal to the maximum width portion d2 of the second inlet portion 15c.

  As described above, the oil separator according to the present embodiment is characterized in that the inlet pipe 15 is divided so that the refrigerant passing through the curved pipe portion 15a flows into the first space 20 and the second space 21, respectively. And Thereby, the refrigerating machine oil contained in the refrigerant flowing into the first space 20 adheres to the inner wall of the shell 11, while the refrigerating machine oil contained in the refrigerant flowing into the second space 21 adheres to the inner wall of the cylindrical member 12. As a result, the oil separator 100 according to the present embodiment can reduce oil droplets drifting in the space without reaching the inner wall, and can further improve the separation characteristics of the refrigerator oil.

  In the present embodiment, it is preferable to make the cylindrical member 12 longer (higher) in order to ensure the turning distance of the refrigerant flowing into the second space 21. For example, it is preferable that the lower end of the cylindrical member 12 has such a length that it does not come into contact with the oil reservoir below the shell 11. Moreover, it is preferable to ensure the length of the shell 11 so that the length of the cylindrical member 12 mentioned above can be ensured.

  Although the embodiments of the present invention have been described above, the present invention is not limited to those shown in the above embodiments.

  The oil separator according to the present invention is suitable for use in an oil separator that separates refrigerating machine oil from refrigerant mixed with refrigerating machine oil for lubricating a compressor used in an air conditioner or the like.

DESCRIPTION OF SYMBOLS 10,100 Oil separator 1,11 Shell 2,12 Cylindrical member 3,13 Upper end plate 4,14 Lower end plate 5,15 Inlet pipe 5a, 15a Curved pipe part 6,16 Outlet pipe 7,17 Return oil pipe 15b First inlet Part 15c Second inlet part 18 Oil droplet 19 Dividing member 20 First space 21 Second space

Claims (3)

A cylindrical container;
An inlet pipe that has a curved pipe part on the upstream side, is connected to the container on the downstream side, and flows a refrigerant mixed with refrigerating machine oil into the container through the curved pipe part;
An outlet pipe connected to the container for allowing the refrigerant separated from the refrigerating machine oil to flow out of the container;
A cylindrical member provided inside the container, having a shape in which the central axis of the container coincides with the central axis, an upper end attached to an upper part of the container, and a lower end opened to a lower space of the container;
A dividing member that divides the inside of the inlet pipe into a first inlet portion and a second inlet portion at a connection portion with the container;
With
The first inlet portion opens into a first space that is a space between an inner wall of the container and an outer wall of the cylindrical member;
The second inlet portion is open to a second space that is a space inside the cylindrical member.
Oil separator. A tangent line on the outer peripheral side of the first inlet portion coincides with a tangent line on the inner wall of the container, and a tangent line on the outer peripheral side of the second inlet portion coincides with a tangent line on the inner wall of the cylindrical member. ,
The oil separator according to claim 1. The cross-sectional area of the first inlet portion and the cross-sectional area of the second inlet portion when cut in a cross section perpendicular to the longitudinal direction of the inlet pipe in the connection portion with the container are equal,
The oil separator according to claim 1 or 2.

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