JP2013238366A - Oil separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil separator capable of promoting improvement in oil separation efficiency while suppressing an increase in cost.SOLUTION: In an oil separator 20 including a device body 21 which has a cylindrical trunk part 211 and in which an upper end opening and lower end opening of the trunk part 211 are respectively closed by an upper lid 212 and a lower lid 213, and an introduction pipe 22 which is connected to a side face of the trunk part 211 such that its central axis L2 horizontally deviates from a central axis L1 of the trunk part 211 to introduce an oil mixed refrigerant into the device body 21, centrifugally separating the oil mixed refrigerant introduced through the introduction pipe 22 into the refrigerant and oil by turning it around the central axis L1 within the trunk part 211, discharging the refrigerant through a refrigerant discharge pipe 23 connected to the upper lid 212, and discharging the oil through an oil discharge pipe 24 connected to the lower lid 213, a curvature of an inner wall surface 222 of the introduction pipe 22 on a side separating from the central axis L1 is formed larger than that of an inner wall surface 221 on a side approaching the central axis L1 of the trunk part 211.

Description

  The present invention relates to an oil separator, and more particularly to an oil separator that is applied to, for example, a refrigerant circuit that circulates refrigerant, and that separates an introduced oil-mixed refrigerant into refrigerant and oil and discharges them separately. Is.

  2. Description of the Related Art Conventionally, there is known an oil separation device that is applied to, for example, a refrigerant circuit that circulates refrigerant and separates an introduced oil-mixed refrigerant into refrigerant and oil and discharges them separately.

  Such an oil separation device includes an apparatus main body, an introduction pipe, a refrigerant discharge pipe, and an oil discharge pipe.

  The apparatus main body has a cylindrical body, and an upper end opening and a lower end opening of the body are closed by an upper lid and a lower lid, respectively. The introduction pipe is for introducing a refrigerant (oil mixture refrigerant) mixed with oil such as lubricating oil, and is connected in a manner extending in a tangential direction at a predetermined connection point on the side surface of the body portion of the apparatus main body. Yes. The refrigerant discharge pipe is connected to the upper lid, and the oil discharge pipe is connected to the lower lid.

  In such an oil separator, the oil-mixed refrigerant introduced through the introduction pipe is swung around the central axis inside the apparatus body to be centrifuged into the gas-phase refrigerant and oil, and the gas-phase refrigerant is discharged from the refrigerant discharge pipe. On the other hand, oil is discharged from the oil discharge pipe.

  By the way, since the cross-sectional shape of the introduction pipe is circular, a mixed fluid of refrigerant and oil flows in the center, and the oil adheres to the inner wall surface due to surface tension. A layer is formed. Then, at the interface between the mixed fluid and the oil layer, droplets are peeled off due to frictional force and oil mist is generated. Therefore, in the introduction pipe, oil mist is generated uniformly over the entire inner wall surface. It will be different.

  Therefore, in the oil separation device, when the oil mixed refrigerant flows into the device main body from the introduction pipe, not only the oil mist is scattered toward the inner wall surface of the device main body but also the oil mist toward the center of the device main body. Since the centrifugal force acting on the oil mist scattered in the central portion is small, the centrifugal separation effect is reduced. As a result, there was a possibility that the oil could not be separated well.

  Therefore, in order to improve the oil separation efficiency, a double tube structure of the inner tube and the outer tube is adopted, the inlet portion of the inner tube is located at the approximate center of the outer tube, and the outlet portion of the inner tube is located closer to the center of the apparatus body. An oil separation device having an introduction pipe that is displaced to contact the outer pipe has been proposed (see, for example, Patent Document 1).

JP-A-5-31438

  However, in the oil separation apparatus proposed in Patent Document 1 as described above, the introduction pipe has a double pipe structure, and the position of the inner pipe is deformed between the inlet side and the outlet side. The pipe structure becomes complicated, and the cost required for materials and processing required for manufacturing the introduction pipe is high, resulting in an increase in cost.

  In view of the above circumstances, an object of the present invention is to provide an oil separation apparatus capable of improving oil separation efficiency while suppressing an increase in cost.

  In order to achieve the above object, an oil separator according to the present invention includes a device body having a cylindrical body portion, and an upper end opening and a lower end opening of the body portion closed by a lid member, and the body portion. And an introduction pipe for introducing an oil-mixed refrigerant into the apparatus main body, and the oil-mixed refrigerant introduced through the introduction pipe is The cylinder is swung around its central axis to be centrifugally separated into refrigerant and oil, and the refrigerant is discharged from a refrigerant discharge pipe connected to a lid member closing the upper end opening of the cylinder. In the oil separation device that discharges oil from an oil discharge pipe connected to a lid member that closes the lower end opening of the part, the introduction pipe is more from the central axis than the inner wall surface on the side close to the central axis of the trunk part The inner wall surface on the separated side is formed with a large curvature. And said that you are.

  Moreover, the present invention is characterized in that, in the oil separating apparatus, a sheet-like capturing member having a large number of small-diameter holes is laid on the inner surface of the body portion.

  According to the oil separation device of the present invention, the introduction pipe is formed such that the curvature of the inner wall surface on the side separated from the central axis is larger than that of the inner wall surface on the side close to the central axis of the trunk portion. As a result of gathering more on the inner wall surface on the side separated by the surface tension, the oil layer formed on the inner wall surface on the separated side is thicker than the oil layer formed on the inner wall surface on the side closer to the central axis It becomes. As a result, the oil mist scattered when flowing into the main body of the apparatus from the introduction pipe increases on the inner wall surface side of the trunk, and the centrifugal force is known to be inversely proportional to the turning radius. The power will increase. As a result, the oil concentration in the vicinity of the inner wall surface of the body portion of the apparatus main body can be increased, and the oil separation efficiency can be improved. In addition, since it is only necessary to change the curvature of the inner wall surface of the introduction pipe, an increase in cost can be suppressed as compared with the conventional double pipe structure. Therefore, it is possible to improve the oil separation efficiency while suppressing an increase in cost.

FIG. 1 is a schematic diagram of a refrigerant circuit to which an oil separation device according to an embodiment of the present invention is applied. FIG. 2 is a side view showing the oil separation device shown in FIG. FIG. 3 is an explanatory view showing a transverse section of a main part of the oil separation device shown in FIG. 2 and a longitudinal section of an introduction pipe constituting the oil separation device. FIG. 4 is an explanatory diagram showing an enlarged main part of the oil separation device shown in FIG. 3. FIG. 5 is an explanatory view showing a modification of the oil separation device according to the embodiment of the present invention.

  Exemplary embodiments of an oil separation device according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram of a refrigerant circuit to which an oil separation device according to an embodiment of the present invention is applied. The refrigerant circuit 10 exemplified here is one in which, for example, carbon dioxide is sealed as a refrigerant, and is configured by sequentially connecting a compressor 11, a radiator 12, an expansion mechanism 13, and an evaporator 14 by piping.

  The compressor 11 sucks the refrigerant through the suction port, compresses the sucked refrigerant to be in a high temperature and high pressure state (high pressure refrigerant), and discharges it from the discharge port. The compressor 11 in the present embodiment is a two-stage compressor that performs a compression operation in two steps. More specifically, the compressor 11 includes a first compression element 111 that performs a first compression operation and a second compression element 112 that performs a second compression operation, and an intermediate heat exchanger therebetween. 113 is provided. The intermediate heat exchanger 113 dissipates the refrigerant compressed by the first compression operation by the first compression element 111 and sends it to the second compression element 112.

  When the refrigerant compressed by the compressor 11 passes through its flow path, the heat radiator 12 exchanges heat with the ambient air to dissipate heat. The expansion mechanism 13 is composed of, for example, a capillary tube or an expansion valve, and decompresses the refrigerant radiated by the radiator 12 to adiabatic expansion. The evaporator 14 evaporates the passing refrigerant, that is, the refrigerant adiabatically expanded by the expansion mechanism 13 to cool the ambient air. The refrigerant evaporated in the evaporator 14 is sucked into the compressor 11.

  Such a refrigerant circuit 10 is provided with an internal heat exchanger 15 and an oil separator 20 in addition to the above configuration. The internal heat exchanger 15 exchanges heat between the high-pressure refrigerant that has passed through the radiator 12 and the refrigerant (low-pressure refrigerant) that has passed through the evaporator 14.

  The oil separator 20 is a so-called oil separator, and is provided between the second compression element 112 and the radiator 12 constituting the compressor 11, and as shown in FIG. , An introduction pipe 22, a refrigerant discharge pipe 23, and an oil discharge pipe 24.

  The apparatus main body 21 includes a cylindrical body 211, an upper lid (lid member) 212 that closes the upper end opening of the body 211, and a lower lid (lid member) 213 that closes the lower end opening of the body 211. I have.

  The introduction pipe 22 is connected in such a manner that the inlet side communicates with a pipe connected to the outlet side of the second compression element 112 of the compressor 11, and the outlet side communicates with the inside of the device main body 21. It is connected to the side surface of the trunk portion 211. More specifically, as shown in FIG. 3, the introduction pipe 22 has an outlet side connected to the side surface of the body portion 211 such that the center axis L2 of the introduction tube 22 is shifted from the center axis L1 of the body portion 211 in the horizontal direction. . Such an introduction pipe 22 is for introducing into the apparatus main body 21 the refrigerant discharged from the compressor 11, that is, the oil-mixed refrigerant of the lubricating oil (oil) discharged from the second compression element 112. is there.

  The introduction tube 22 has a uniform tube wall thickness, and has a shape in which the longitudinal sectional shape in the direction orthogonal to the central axis L2 is asymmetrical in the left-right direction. More specifically, the introduction pipe 22 is a side (hereinafter also referred to as a separation side) that is farther from the central axis L1 than an inner wall surface 221 that is closer to the central axis L1 (hereinafter also referred to as the central side) of the body 211. The inner wall surface 222 is formed to have a large curvature.

  The refrigerant discharge pipe 23 is connected in such a manner that the inlet side is connected to the upper lid 212 in a mode communicating with the inside of the apparatus main body 21 and the outlet side is connected to a pipe connected to the inlet side of the radiator 12. The oil discharge pipe 24 is connected to the lower lid 213 in such a manner that the inlet side communicates with the inside of the apparatus main body 21, the outlet side branches into two, one is connected to the first compression element 111, and the other is the second Connected to the compression element 112.

  In the oil separator 20 having the above-described configuration, an oil mixed refrigerant that is a mixture of the high-temperature and high-pressure refrigerant compressed and discharged by the compressor 11 and the oil discharged together with the high-temperature and high-pressure refrigerant passes through the introduction pipe 22. When introduced into the apparatus main body 21 (body 211), the oil-mixed refrigerant is swung around the central axis L1 of the body 211 to be centrifuged into refrigerant (high-temperature and high-pressure refrigerant) and oil.

  The refrigerant (gas phase refrigerant) separated by the centrifugal separation is discharged from the refrigerant discharge pipe 23 to reach the radiator 12, and radiates heat by exchanging heat with the surrounding air by the radiator 12. The refrigerant radiated by the radiator 12 is adiabatically expanded by the expansion mechanism 13 after passing through the internal heat exchanger 15, and reaches the evaporator 14 as a low-temperature and low-pressure refrigerant. The refrigerant that has reached the evaporator 14 evaporates by exchanging heat with the ambient air, and then is sucked into the compressor 11 (to the first compression element 111) through the internal heat exchanger 15.

  The oil adhering to the inner wall surface of the body 211 by the centrifugal separation flows downward and is discharged from the oil discharge pipe 24. The oil discharged from the oil discharge pipe 24 branches into two according to the oil discharge pipe 24, and one is sucked by the first compression element 111 and the other is sucked by the second compression element 112.

  By the way, in the inside of the introduction pipe 22, the fluid mixture of the refrigerant and oil flows in the center, and the oil layer is formed on the inner wall surface by the oil adhering due to surface tension. Since the introduction pipe 22 is formed so that the curvature of the separation-side inner wall surface 222 is larger than that of the center-side inner wall surface 221, the adhering oil gathers in the larger curvature due to the surface tension. As shown, the oil layer OS formed on the remote inner wall surface 222 is thicker than the oil layer OS formed on the central inner wall surface 221. That is, the oil concentration distribution on the outer side in the radial direction of the apparatus main body 21 is made larger than that on the inner side in the radial direction before being introduced into the apparatus main body 21.

  As a result, it is known that the oil mist OM scattered when flowing into the apparatus main body 21 from the introduction pipe 22 increases on the inner wall surface side of the apparatus main body 21 (body 211), and the centrifugal force is inversely proportional to the turning radius. Therefore, the centrifugal force acting on the oil mist OM increases. As a result, the oil concentration in the vicinity of the inner wall surface of the body 211 of the apparatus main body 21 can be increased, and the oil separation efficiency can be improved. In addition, since it is only necessary to change the curvature of the introduction side wall 221, the center side inner wall surface 221 and the separation side inner wall surface 222, it is possible to suppress an increase in cost compared to the conventional double tube structure. be able to.

  Therefore, according to the oil separation device 20 according to the embodiment of the present invention, it is possible to improve the oil separation efficiency while suppressing an increase in cost.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made.

  For example, as shown in FIG. 5, a sheet-like capturing member 30 such as a punching metal or the like having a mesh-structured mesh material or a large number of small-diameter holes may be laid on the inner wall surface of the body portion 211. According to such a configuration, by increasing the contact area with the oil mist OM along the inner wall surface of the apparatus main body 21, the oil concentration on the inner wall surface of the apparatus main body 21 can be increased, and the oil separation efficiency can be increased. Can be improved.

  In the embodiment described above, the introduction pipe 22 has a uniform thickness on the pipe wall. However, in the present invention, the introduction pipe 22 is further away from the central axis than the inner wall surface on the side close to the central axis of the trunk. As long as the curvature of the inner wall surface on the separated side is increased, the thickness of the tube wall may be changed.

DESCRIPTION OF SYMBOLS 10 Refrigerant circuit 11 Compressor 111 1st compression element 112 2nd compression element 113 Intermediate heat exchanger 12 Radiator 13 Expansion mechanism 14 Evaporator 15 Internal heat exchanger 20 Oil separator 21 Apparatus body 211 Body 212 Upper lid (lid member) )
213 Lower lid (lid member)
22 Introduction pipe 221 Center side inner wall surface 222 Separation side inner wall surface 23 Refrigerant discharge pipe 24 Oil discharge pipe 30 Trapping member OM Oil mist OS Oil layer

Claims (2)

An apparatus main body having a cylindrical body, and an upper end opening and a lower end opening of the body being closed by a lid member;
An inlet pipe for introducing an oil-mixed refrigerant into the apparatus main body, connected to the side surface of the barrel part so that its own central axis is displaced horizontally with respect to the central axis of the trunk part;
Refrigerant connected to a lid member that closes the upper end opening of the barrel part by centrifuging the oil-mixed refrigerant introduced through the introduction pipe around the central axis inside the barrel part to be centrifuged into refrigerant and oil. In the oil separator for discharging the refrigerant from the oil discharge pipe connected to the lid member that closes the lower end opening of the trunk while discharging the refrigerant from the discharge pipe,
The oil separator according to claim 1, wherein the introduction pipe is formed such that the curvature of the inner wall surface on the side separated from the central axis is larger than the inner wall surface on the side close to the central axis of the body portion.   2. The oil separation device according to claim 1, wherein a sheet-like capturing member having a large number of small-diameter holes is laid on the inner surface of the body portion.

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