OIL SEPARATOR

Abstract

An oil separator includes a capturing member inside a main body container, which includes a first capturing member portion arranged on a side closer to an inflow pipe and a second capturing member portion being arranged on a side closer to an outflow pipe and having a porosity smaller than that of the first capturing member portion. Therefore, a driving force is generated by the capturing member having the different porosities. Through the driving force, a force of gravity, and a capillary phenomenon, oil inside the main body container is transported to an oil return pipe to prevent re-scattering of the oil, thereby being capable of suppressing reduction in oil separation efficiency. At the same time, oil return efficiency to the compressor is improved.

Claims

1. An oil separator, which is to be connected to a discharge pipe of a compressor of a refrigeration circuit and is configured to separate oil contained in refrigerant discharged from the compressor from the refrigerant, comprising: a main body container; an inflow pipe being connected to an upper side of the main body container and having an end connected to the discharge pipe, and being configured to guide the refrigerant and the oil into the main body container; an outflow pipe having an end connected to the main body container, and being configured to cause the refrigerant inside the main body container to flow out; an oil return pipe having an end connected to the lower side of the main body container, and being configured to return the oil inside the main body container to the compressor; and a capturing member, which is provided on an inner wall surface of the main body container, and is configured to capture the oil flowing into the main body container through the inflow pipe, wherein the capturing member includes a first capturing member portion arranged on a side closer to the inflow pipe and a second capturing member portion being arranged on a side closer to the outflow pipe and having a porosity smaller than that of the first capturing member portion.

2. An oil separator according to claim 1, further comprising a swirl flow forming unit, which is provided inside the inflow pipe and is configured to generate a swirl flow in the oil and the refrigerant.

3. An oil separator according to claim 2, wherein the swirl flow forming unit comprises swirl vanes.

4. An oil separator according to claim 1, wherein the inflow pipe comprises a helical-groove pipe having a helical groove formed in an inner wall surface.

5. An oil separator according to claim 1, wherein at least one of the inner wall surface or an outer wall surface of the main body container has a concave and convex surface formed thereon.

6. An oil separator according to claim 1, wherein at least one of an inner wall surface or an outer wall surface of the oil return pipe has a concave and convex surface formed thereon.

7. An oil separator according to claim 1, wherein the outflow pipe is arranged on the same axis as the inflow pipe below the inflow pipe.

8. An oil separator according to claim 1, wherein the refrigerant comprises a refrigerant which contains a polymer obtained by polymerization of double bonds.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0027] FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus using an oil separator according to Embodiment 1 of the present invention.

[0028] FIG. 2 is a perspective view for illustrating the oil separator illustrated in FIG. 1.

[0029] FIG. 3 is an explanatory view for illustrating movements of refrigerant and oil inside the oil separator illustrated in FIG. 1.

[0030] FIG. 4 is a perspective view for illustrating a first modification example of the oil separator according to Embodiment 1 of the present invention.

[0031] FIG. 5 is an explanatory view for illustrating movements of refrigerant and oil inside the oil separator illustrated in FIG.

[0032] 4.

[0033] FIG. 6 is a perspective view for illustrating a second modification example of the oil separator according to Embodiment 1 of the present invention.

[0034] FIG. 7 is an explanatory view for illustrating movements of refrigerant and oil inside the oil separator illustrated in FIG. 6.

[0035] FIG. 8 is an explanatory view for illustrating movements of refrigerant, oil, and a polymer inside an oil separator, which is a third modification example of the oil separator according to Embodiment 1 of the present invention.

[0036] FIG. 9 is an explanatory view for illustrating movements of refrigerant and oil inside an oil separator, which is an oil separator according to Embodiment 2 of the present invention.

[0037] FIG. 10A, FIG. 10B, and FIG. 10C are partial sectional views for illustrating various wall portions of a main body container illustrated in FIG. 9.

[0038] FIG. 11 is an explanatory view for illustrating movements of refrigerant and oil inside an oil separator, which is a modification example of the oil separator according to Embodiment 2 of the present invention.

[0039] FIG. 12 is a partially cut-away view of an oil return pipe illustrated in FIG. 11.

DESCRIPTION OF EMBODIMENTS

[0040] Now, an oil separator according to embodiments of the present invention is described with reference to the drawings. Note that, in the drawings, the same reference symbols represent the same or corresponding members and parts.

Embodiment 1

[0041] FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus using an oil separator 5 according to Embodiment 1 of the present invention.

[0042] The air-conditioning apparatus includes a compressor 1, the oil separator 5, a four-way valve 6, an evaporator 4, an expansion valve 3, and a condenser 2 connected via a refrigerant pipe 7 through which refrigerant flows.

[0043] During a heating operation, the four-way valve 6 (dotted lines in FIG. 1) is switched so that the refrigerant circulates the compressor 1, the oil separator 5, the four-way valve 6, the evaporator 4, the expansion valve 3, and the condenser 2 in the stated order through the refrigerant pipe 7.

[0044] Further, during a cooling operation, the four-way valve 6 (solid lines in FIG. 1) is switched so that the refrigerant circulates the compressor 1, the oil separator 5, the four-way valve 6, the condenser 2, the expansion valve 3, and the evaporator 4 in the stated order through the refrigerant pipe 7.

[0045] FIG. 2 is a perspective view for illustrating the oil separator 5.

[0046] The oil separator 5 includes a main body container 52 having a cylindrical shape, an inflow pipe 51, which has one end connected to an upper side of the main body container 52 and another end connected to a discharge pipe of the compressor 1 and is configured to guide gaseous refrigerant and oil into the main body container 52, an outflow pipe 54, which has an end connected to a lower side of the main body container 52 and is configured to cause the refrigerant in the main body container 52 to flow out, an oil return pipe 55 having a base end connected to a lower edge portion of the main body container 52 and a distal end extending downward in a vertical direction, and a capturing member 53, which is provided on an inner wall surface of the main body container 52 and is configured to capture the oil flowing thereinto through the inflow pipe 51.

[0047] A specific example of the capturing member 53 is, for example, a foam metal.

[0048] The capturing member 53 includes a first capturing member portion 531 arranged on a side closer to the inflow pipe 51, which is an upstream of the main body container 52, and a second capturing member portion 532 being arranged on a side closer to the outflow pipe 54, which is a downstream of the main body container 52, and having a porosity smaller than that of the first capturing member portion 531.

[0049] The outflow pipe 54, which is arranged on the same axial line as that of the inflow pipe 51, is connected to the condenser 2 via a second pipe 102.

[0050] The oil return pipe 55 is connected to a third pipe 103 between the compressor 1 and the evaporator 4.

[0051] In the oil separator 5 according to Embodiment 1, through drive of the compressor 1, high-temperature and high-pressure gaseous refrigerant and oil discharged from the discharge pipe of the compressor 1 flow into the inflow pipe 51 of the oil separator 5 through the first pipe 101 and subsequently flow into an interior of the main body container 52.

[0052] The refrigerant of the refrigerant and the oil having flowed into the interior of the main body container 52 flows from the main body container 52 directly into the outflow pipe 54 as indicated by the arrows A in FIG. 3 to be sent to the condenser 2.

[0053] Meanwhile, in-container oil 200 in the main body container 52 is scattered in a direction toward an inner wall of the main body container 52, as indicated by the arrows B in FIG. 3.

[0054] The in-container oil 200 scattered in the direction toward the inner wall is captured by the first capturing member portion 531 of the capturing member 53 installed on the inner wall under a surface tension and flows into an interior of the first capturing member portion 531 by a capillary phenomenon.

[0055] In the inflow in-container oil 200, a driving force from the first capturing member portion 531 having a large porosity to the second capturing member portion 532 having a small porosity is generated. Through the driving force, the capillary phenomenon, and a force of gravity, the in-container oil 200 is transported from the first capturing member portion 531 to the second capturing member portion 532.

[0056] The transported in-container oil 200 flows into the oil return pipe 55 due to a difference in pressure between the main body container 52 and the oil return pipe 55 . The in-container oil 200 subsequently flows into the third pipe 103 between the compressor 1 and the evaporator 4 from the oil return pipe 55 to be returned to the compressor 1.

[0057] According to the oil separator 5 of Embodiment 1 described above, the in-container oil 200 is captured by the first capturing member portion 531. The driving force is generated by the capturing member 53 having the different porosities. Through the driving force, the capillary phenomenon, and the force of gravity, the oil is transported to the oil return pipe 55. In this manner, re-scattering is prevented, thereby being capable of suppressing reduction in oil separation efficiency. At the same time, oil return efficiency to the compressor 1 is improved.

[0058] Although an inner diameter of the inflow pipe 51 and an inner diameter of the outflow pipe 54 are smaller than an inner diameter of the main body container 52, rapid expansion of the refrigerant between the inflow pipe 51 and the main body container 52 and rapid compression of the refrigerant between the main body container 52 and the outflow pipe 54 do not occur. Thus, a pressure loss of the refrigerant is suppressed.

[0059] The inflow pipe 51 and the outflow pipe 54 are arranged on the same axial line. The refrigerant having flowed into the main body container 52 through the inflow pipe 51 flows directly into the outflow pipe 54 without any forcible change of a flow of the refrigerant inside the main body container 52. Thus, the pressure loss of the refrigerant is suppressed.

[0060] FIG. 4 is a perspective view for illustrating a first modification example of the oil separator 5 according to Embodiment 1 of the present invention. A swirl flow forming unit 56, which is provided inside the inflow pipe 51, and is configured to generate a swirl flow in the refrigerant and the in-container oil 200. The swirl flow forming unit 56 includes, for example, swirl vanes.

[0061] Other configuration is the same as the configuration of the oil separator illustrated in FIG. 2.

[0062] In this example, the high-temperature and high-pressure gaseous refrigerant and oil discharged by the drive of the compressor 1 flow into the inflow pipe 51 of the oil separator 5. In the refrigerant and the oil, a swirl flow is generated inside the inflow pipe 51 by the swirl flow forming unit 56, as illustrated in FIG. 5.

[0063] Then, the refrigerant of the refrigerant and the oil flowing into the interior of the main body container 52 flows from the main body container 52 directly into the inflow pipe 54 as indicated by the arrows A of FIG. 5 to be sent to the condenser 2.

[0064] Meanwhile, the in-container oil 200 inside the main body container 52 is scattered in the direction toward the inner wall of the main body container 52 by a centrifugal force of the swirl flow to be guided to the first capturing member portion 531 having the large porosity.

[0065] The guided in-container oil 200 is captured by the first capturing member portion 531 under the surface tension, and is then transported from the first capturing member portion 531 to the second capturing member portion 532 by the driving force, the capillary phenomenon, and the force of gravity.

[0066] Subsequent movement of the in-container oil 200 is the same as that in the oil separator 5 illustrated in FIG. 2.

[0067] According to the oil separator 5 of this embodiment, the in-container oil 200 is guided by the swirl flow to the first capturing member portion 531 having the large porosity. Thereafter, the in-container oil 200 is transported to the oil return pipe 55 through the same movement as in the oil separator 5 illustrated in FIG. 2. Similarly to the oil separator 5 illustrated in FIG. 2, the re-scattering of the oil is prevented, thereby being capable of suppressing reduction in oil separation efficiency. At the same time, the effect of improving the oil return efficiency to the compressor is obtained.

[0068] FIG. 6 is a perspective view for illustrating a second modification example of the oil separator according to Embodiment 1 of the present invention, in which the inflow pipe 51 is a helical-groove pipe 57 having helical grooves formed in an inner wall surface.

[0069] Other configuration is the same as the configuration of the oil separator 5 illustrated in FIG. 2.

[0070] In this example, the high-temperature and high-pressure gaseous refrigerant and oil discharged by the drive of the compressor 1 flow into the inflow pipe 51 of the oil separator 5. In the refrigerant and the oil, a swirl flow is generated inside the inflow pipe 51 being the helical-groove pipe 57 as illustrated in FIG. 7.

[0071] Then, the refrigerant of the refrigerant and the in-container oil 200 having flowed into the interior of the main body container 52 flows from the main body container 52 directly into the inflow pipe 54 as indicated by the arrows A of FIG. 7 to be sent to the condenser 2.

[0072] Meanwhile, the in-container oil 200 inside the main body container 52 is scattered in the direction toward the inner wall of the main body container 52 by a centrifugal force of the swirl flow to be guided to the first capturing member portion 531 having the large porosity. The guided oil is captured by the first capturing member portion 531 under the surface tension, and is then transported from the first capturing member portion 531 to the second capturing member portion 532 by the driving force, the capillary phenomenon, and the force of gravity.

[0073] Subsequent movement of the in-container oil 200 is the same as that in the oil separator 5 illustrated in FIG. 2.

[0074] According to the oil separator 5 of this embodiment, the helical-groove pipe 57 configured to generate the swirl flow is used as the inflow pipe 51. As a result, the same effects as those obtained by the oil separator 5 illustrated in FIG. 2 can be obtained.

[0075] Further, the swirl flow forming unit 56 including the swirl vanes is not required to be provided inside the inflow pipe 51 unlike the first modification example of Embodiment 1. Therefore, the swirl flow can be generated with a simple configuration. As a result, the pressure loss of the refrigerant inside the inflow pipe 51 can be reduced.

[0076] FIG. 8 is a perspective view for illustrating a third modification example of the oil separator 5 according to Embodiment 1 of the present invention.

[0077] In this example, in a refrigerant circuit, a refrigerant (for example, HFO-1123) having a composition which contains a polymer obtained by polymerization of double bonds is enclosed in the refrigeration circuit.

[0078] Other configuration is the same as that of the oil separator 5 illustrated in FIG. 2.

[0079] In the oil separator 5 according to the third modification example, by the drive of the compressor 1, the high-temperature and high-pressure gaseous refrigerant, oil, and polymer are discharged, flow into the inflow pipe 51 of the oil separator 5, and flow from the inflow pipe 51 into the main body container 52. Among those, the refrigerant flows from the main body container 52 directly into the outflow pipe 54, as indicated by the arrows A.

[0080] Meanwhile, the in-container oil 200, as indicated by the arrows B, and a polymer 201, as indicated by the arrows C, are scattered in the direction toward the inner wall of the main body container 52.

[0081] The oil 200 and the polymer 201 scattered in the direction toward the inner wall are captured by the first capturing member portion 531 installed on the inner wall under the surface tension. The in-container oil 200 flows down to the second capturing member portion 532 by the capillary phenomenon, whereas the polymer 201 is stored inside the main body container 52 after being captured by the capturing member 53.

[0082] In the inflow in-container oil 200, the driving force from the first capturing member portion 531 having the large porosity to the second capturing member portion 532 having the small porosity is generated. By the driving force, the capillary phenomenon, and the force of gravity, the in-container oil 200 is transported from the first capturing member portion 531 to the second capturing member portion 532.

[0083] Subsequent movement of the oil 200 is the same as that in the oil separator 5 illustrated in FIG. 2.

[0084] In this modification example, the polymer 201 is stored at the bottom inside the oil separator 5. In this manner, the polymer 201 can be prevented from flowing into the condenser 2 or the evaporator 4, thereby being capable of suppressing reduction in heat transfer performance in the condenser 2 and the evaporator 4.

[0085] Further, the polymer 201 is stored in the oil separator 5. In this manner, the polymer 201 can be prevented from flowing into the expansion valve 3, thereby being capable of suppressing reduction in control performance of the expansion valve 3.

Embodiment 2

[0086] FIG. 9 is a configuration diagram for illustrating the oil separator 5 according to Embodiment 2 of the present invention.

[0087] In Embodiment 2, a surface area of a main body container 520 of the oil separator 5 is increased.

[0088] As specific examples, a wall portion 520a having a concave and convex surface as an outer wall surface is illustrated in FIG. 10A, a wall portion 520b having a concave and convex surface as an inner wall surface is illustrated in FIG. 10B, and a wall portion 520c having concave and convex surfaces as both of the outer wall surface and the inner wall surface is illustrated in FIG. 10C.

[0089] Other configuration is the same as that of the oil separator 5 of Embodiment 1.

[0090] Movements of the refrigerant and the in-container oil 200 is the same as that in the oil separator 5 illustrated in FIG. 2.

[0091] According to the oil separator 5 of Embodiment 2, the same effects as those obtained by the oil separator 5 of Embodiment 1 can be obtained. At the same time, the in-container oil 200 returned to the compressor 1 through the oil return pipe 55 is transported by the capturing member 53 provided on the inner wall of the main body container 520. Through increase in surface area of the main body container 52, the in-container oil 200 is caused to efficiently reject heat during the transport. As a result, suction SH (degree of superheat) is not increased, thereby being capable of suppressing reduction in efficiency of the compressor 1.

[0092] FIG. 11 is a view for illustrating a modification example of the oil separator 5 according to Embodiment 2 of the present invention, and FIG. 12 is a partially cut-away view of an oil return pipe 550 illustrated in FIG. 11.

[0093] In the modification example of Embodiment 2, in order to increase the surface area of the oil return pipe 550, a convex and concave surface formed with helical grooves is formed on an inner wall surface of the oil return pipe 550 of the oil separator 5.

[0094] Movements of the gas refrigerant and the in-container oil 200 is the same as that in the oil separator 5 according to Embodiment 1.

[0095] According to the modification example of the oil separator 5 of Embodiment 2, the same effects as those obtained by the oil separator 5 illustrated in FIG. 2 can be obtained.

[0096] Through increase in surface area of the oil return pipe 550, the in-container oil 200 is caused to efficiently reject heat while passing through the oil return pipe 550. As a result, the suction SH (degree of superheat) is not increased, thereby being capable of suppressing reduction in efficiency of the compressor 1.

[0097] As compared to the main body container 520 illustrated in FIG. 9 in which the surface area is increased by forming the concave and convex surface on the surface, the main body container 52 has a small surface area in this example. Therefore, heat rejection of the refrigerant inside the main body container 52 is suppressed, and the refrigerant is then sent to the condenser 2. Thus, reduction in heat exchange performance in the condenser 2 can be suppressed.

[0098] The oil separator 5 used for the air-conditioning apparatus is described in each of the above-mentioned embodiments. However, as a matter of course, the oil separator 5 is not limited thereto. The oil separator 5 can also be used for, for example, a refrigerating machine.

[0099] The capturing member 53 includes the first capturing member portion 531 and the second capturing member portion 532 in each of the embodiments described above. However, a third capturing member portion having a smaller porosity than that of the second capturing member portion 532 may be arranged adjacent to the second capturing member portion 532.

[0100] The capturing member may have the porosity continuously decreasing toward the lower side of the main body container 52.

REFERENCE SIGNS LIST

[0101] 1 compressor, 2 condenser, 3 expansion valve, 5 oil separator, 6 four-way valve, 7 refrigerant pipe, 51 inflow pipe, 52, 520 main body container, 520a, 520b, 520c wall portion, 53 capturing member, 531 first capturing member portion, 532 second capturing member portion, 54 outflow pipe, 55, 550 oil return pipe, 56 swirl flow forming unit, 57 helical-groove pipe, 101 first pipe, 102 second pipe, 200 in-container oil, 201 polymer