JP2011202876A - Centrifugal oil separator and outdoor unit of air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal oil separator reducing its size and weight without degrading oil separating performance.SOLUTION: This centrifugal oil separator 100 includes a container body 1 having a cylindrical part 1a, an inlet pipe 2 connected in the tangential direction of an inner wall surface of the cylindrical part at an upper part of the cylindrical part of the container body, an outlet pipe 3 connected to the upper part of the container body by being inserted coaxially with the container body, and a discharge pipe 4 connected to a lower part of the container body. This centrifugal oil separator is configured to satisfy 0.40≤d/D≤0.44, when a diameter of the inlet pipe is d, and a diameter of the cylindrical part of the container body is D.

Description

  The present invention relates to a centrifugal oil separator and an air conditioner outdoor unit that centrifuge oil contained in a gas, and in particular, a centrifugal oil separator that is mounted on an air conditioner or a refrigeration apparatus using a high-pressure refrigerant. Is suitable.

  As this type of centrifugal separator, there is one described in Japanese Patent Application Laid-Open No. 2004-169983 (Patent Document 1). The thing of this patent document 1 describes centrifuging the refrigerating machine oil contained in the gas refrigerant discharged from the compressor with a centrifugal oil separator.

JP 2004-169983 A

  In recent years, in air conditioners for stores and offices, the number of multi-units for connecting a plurality of indoor units to one outdoor unit has increased, and as a result, refrigerant piping for connecting the outdoor unit and the indoor unit (local refrigerant) The length of piping is also getting longer. For this reason, since the refrigeration oil which flowed out with the refrigerant gas from the compressor stays in the refrigerant pipe and the heat exchanger of the indoor unit, and it becomes difficult to return to the compressor, securing the amount of refrigeration oil in the compressor becomes an issue. ing.

  In order to solve this problem, as described in Patent Document 1, it is known to provide an oil separator on the discharge side of the compressor, that is, in the outdoor unit. However, the outdoor unit is reduced in size and weight. When trying to do so, there was a problem that it was difficult to secure a space for accommodating the oil separator, and it was difficult to reduce the size and weight of the outdoor unit.

  An object of the present invention is to obtain a centrifugal oil separator that can be reduced in size and weight without deteriorating oil separation performance.

  Another object of the present invention is to obtain an outdoor unit equipped with a centrifugal oil separator that can be reduced in size and weight.

  Still another object of the present invention is to provide a centrifugal oil separator that can improve oil separation performance and can be reduced in size and weight.

In order to achieve the above object, the present invention provides a container body having a cylindrical portion, an introduction pipe connected at an upper portion of the cylindrical portion of the container body in a tangential direction of an inner wall surface of the cylindrical portion, and an upper portion of the container body. In addition, in a centrifugal oil separator comprising a lead-out pipe inserted and connected so as to be coaxial with the container body, and a discharge pipe connected to the lower part of the container body, the diameter of the introduction pipe is d, when the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
It is comprised so that it may become.

Another feature of the present invention is that a container body having a cylindrical portion, a tapered portion formed integrally with the upper and lower portions of the cylindrical portion, and an inner wall surface of the cylindrical portion at the upper portion of the cylindrical portion. An introduction pipe connected in a tangential direction; an outlet pipe connected to the upper portion of the container main body so as to be coaxial with the container main body; and a discharge pipe connected to the lower portion of the container main body. In the centrifugal oil separator, when the diameter of the introduction pipe is d and the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
And the lower end position in the container body of the outlet pipe and the upper end position of the tapered portion at the lower part of the container body are substantially the same position in the height direction.

According to still another aspect of the present invention, in the outdoor unit of an air conditioner including a compressor, an oil separator, an outdoor heat exchanger, and an outdoor expansion valve, the oil separator is provided on a discharge side of the compressor and discharged. A centrifugal oil separator that centrifuges refrigeration oil from the refrigerant gas and returns it to the suction side of the compressor, the centrifugal oil separator comprising: a container body having a cylindrical portion; and An inlet pipe connected to a tangential direction of an inner wall surface of the cylindrical portion at an upper portion of the cylindrical portion, and for introducing a refrigerant gas discharged from the compressor into the container main body; A lead-out pipe for allowing refrigerant gas, which is inserted and connected so as to be coaxial with the main body and from which the refrigerating machine oil is separated in the container main body, to flow out of the container, and the refrigerating machine oil separated from the refrigerant gas in the container main body To return the container to the compressor When the provided connected to the oil return pipe to the lower, the diameter of the inlet tube to d, the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
It is that it was constituted so that.

  According to the present invention, it is possible to obtain a centrifugal oil separator that can be reduced in size and weight without reducing the oil separation performance or while improving the oil separation performance.

  Moreover, according to the outdoor unit of the air conditioning apparatus of this invention, there exists an effect which can achieve size reduction and weight reduction of an outdoor unit.

The longitudinal cross-sectional view which shows Example 1 of the centrifugal oil separator of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. The figure which shows the whole structure of an air conditioning apparatus. The diagram which shows the relationship between ratio (d / D) of the diameter d of an introductory tube, and the diameter D of a container main body, and oil separation efficiency. FIG. 5 is a view showing another example of the centrifugal oil separator shown in the first embodiment and corresponding to the AA cross section of FIG. 1. The refrigeration cycle block diagram which shows an example of an air conditioning apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 3 is a diagram showing the overall configuration of the air conditioner. In the figure, 5 is an outdoor unit, 6 is an indoor unit, and the outdoor unit 5 and the indoor unit 6 are connected by local refrigerant pipes 7 and 8. . 7 is a gas side refrigerant pipe, 8 is a liquid side refrigerant pipe, and the diameter φ of the gas side refrigerant pipe is larger than the liquid side refrigerant pipe diameter.

FIG. 6 is a configuration diagram of a refrigeration cycle of a general air conditioner, in which 5 is an outdoor unit and 6 is an indoor unit.
The outdoor unit 5 includes a compressor 10, an oil separator 100, a four-way valve 11, an outdoor heat exchanger 12, an outdoor expansion valve 13, a liquid tank 14, a liquid blocking valve 15, a gas blocking valve 16, a gas-liquid separator 17, and the like. The refrigerant pipe 18 is connected. In addition, 19 is an outdoor fan, 20 and 21 are temperature detectors, and 22 and 23 are pressure detectors. The lower part of the oil separator 100 and the upstream side of the gas-liquid separator 17 are connected by an oil return pipe 4, and a throttle mechanism 24 is provided in the oil return pipe 4.

The indoor unit 6 includes an indoor heat exchanger 25, an indoor expansion valve 26, an indoor fan 27, a temperature detector 28, and the like.
The outdoor unit 5 and the indoor unit 6 are connected by a gas-side refrigerant pipe 7 and a liquid-side refrigerant pipe 8 which are local refrigerant pipes.

  The refrigerant compressed by the compressor 10 flows into the oil separator 100, and the refrigerating machine oil contained in the refrigerant gas is separated. The refrigerant gas flows into the four-way valve 11 and is outdoor during cooling. It flows to the heat exchanger 12 side, and flows to the indoor heat exchanger 25 side of the indoor unit 6 during heating. The refrigerating machine oil separated by the oil separator 100 is returned to the upstream side of the gas-liquid separator 17 which is the suction side of the compressor 10 via the oil return pipe 4 and the throttle mechanism 24, and again the compressor 10 It has a configuration that flows inside.

  The refrigerating machine oil that could not be separated by the oil separator circulates in the refrigeration cycle together with the refrigerant. However, if it adheres to the inner surface of the outdoor heat exchanger 12 or the indoor heat exchanger 25, the refrigerant exchanges heat. The oil separator 100 is installed for the purpose of reducing the amount of oil circulating in the refrigeration cycle as much as possible. In this example, the separated refrigeration oil is returned to the upstream side of the gas-liquid separator 17, but may be returned between the compressor 10 and the gas-liquid separator 17.

The oil separator 100 shown in FIG. 6 uses a centrifugal oil separator. Specific examples of the centrifugal oil separator according to the present invention will be described with reference to FIGS.
1 is a longitudinal sectional view of a centrifugal oil separator showing Embodiment 1 of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.

  1 and 2, reference numeral 1 denotes a container body having a cylindrical portion 1a. A cylindrical body is drawn into a tapered shape at its upper end side and lower end side to form an upper tapered portion 1b and a lower tapered portion 1c. ing. Reference numeral 2 denotes an introduction pipe connected in the tangential direction of the inner wall surface of the cylindrical portion at the upper portion of the cylindrical portion. That is, the introduction tube 2 is inserted through the cylindrical portion (the portion not having the tapered shape) of the container body 1 in the tangential direction of the inner wall surface. Reference numeral 3 denotes a lead-out pipe that is inserted and connected to the upper part of the container body 1 so as to be coaxial with the container body. That is, the lead-out pipe 3 penetrates the center of the upper taper portion 1b of the container body 1 and is inserted deep into the container, and the center line of the lead-out pipe 3 and the container body 1 is arranged so as to be coaxial. ing. Reference numeral 4 denotes a discharge pipe (oil return pipe) connected to the lower portion of the container main body 1. The discharge pipe 4 is fixed to the center of the lower tapered portion 1c, and the center line of the discharge pipe 4 and the container main body 1 is coaxial. Is placed on top.

  The gas-liquid two-phase flow of the refrigerant gas and the refrigerating machine oil discharged from the compressor flows into the container body 1 from the introduction pipe 2. The gas-liquid two-phase flow that flows into the container body 1 descends while spirally turning along the inner surface of the container body. The refrigerating machine oil adheres to the inner surface of the container body 1 due to the centrifugal force generated by the swirling and is separated from the refrigerant gas. The refrigerant gas from which the refrigerating machine oil has been separated is led out from the lead-out pipe 3 to the refrigeration cycle. The refrigerating machine oil adhering to the inner surface of the container body 1 descends along the inner surface of the container due to gravity, and is discharged from the discharge pipe (oil return pipe) 4 and returned to the suction side of the compressor.

In this embodiment, the configuration of the centrifugal oil separator is as follows. That is, when the diameter of the cylindrical portion 1a of the container body 1 is D and the height dimension from the end of the upper tapered portion 1b to the end of the lower tapered portion 1c is H, the height dimension H is cylindrical. More than 5 times the diameter D of the portion 1a, that is,
H ≧ 5D
It is said. Further, the height dimension H can be minimized by inserting the lower end of the outlet pipe 3 to the vicinity of the upper portion of the lower tapered portion of the container body 1. That is, the longer the dimension from the position of the inlet pipe 2 to the lower end position of the outlet pipe 3, the longer the distance that the refrigerant gas containing oil swirls and flows, so that more oil can be separated. This is because the separation performance can be improved.

  A particularly important feature in this embodiment is the relationship between the diameter d of the introduction pipe 2 and the diameter D of the cylindrical portion 1a of the container body. FIG. 4 is a diagram showing the relationship between the ratio (d / D) between the diameter d of the introduction pipe and the diameter D of the container body and the oil separation efficiency. The experimental data shown in FIG. 4 is an experiment using a container body 1 having a height H of 5 times or more than the diameter D of the container body. Here, the oil separation efficiency is the ratio of the flow rate of refrigerating machine oil discharged per unit time from the discharge pipe (oil return pipe) 4 to the inflow amount of refrigerating machine oil per unit time flowing into the oil separator. .

  In a conventional centrifugal oil separator, the ratio (d / D) is 0.375 (37.5%) even if it is large, and is usually less than that. However, when the ratio (d / D) was variously changed and experimented, as shown in FIG. 4, the oil separation efficiency was drastically improved from around 40.5%, and the peak at around 42.8% was 44%. It has been found that the oil separation efficiency is drastically reduced when the above is reached. Conventionally, it has been considered that the separation efficiency is improved as the diameter D of the container body is larger and the height dimension H of the container body is larger. However, as a result of the experiment, the diameter D of the container body may be increased. However, as shown in FIG. 4, it has been found that there is a range in which the oil separation efficiency can be improved in relation to the diameter d of the introduction pipe. Examining the reason for the results shown in FIG. 4, since the turning radius decreases as the diameter D of the container body decreases, if the flow velocity of the refrigerant gas flowing from the introduction pipe is the same, the centrifugal force increases. This is thought to be due to an increase in centrifugal action. However, if the diameter D of the container body is too small, the area where the introduction pipe 2 and the outlet pipe 3 overlap increases, and the outlet portion of the outlet pipe 2 and the side surface of the outlet pipe 3 are too close to each other. The reason is considered to be that turbulent flow occurs and the oil separation efficiency decreases rapidly. Further, since the noise increases with the turbulent flow due to the collision, the ratio (d / D) is 0.44 or less, preferably 0.43 or less.

From the result of FIG. 4, the ratio (d / D) between the diameter d of the introduction tube and the diameter D of the container body is
0.40 ≦ d / D ≦ 0.44
If the refrigerant gas flow rate introduced into the centrifugal oil separator is the same (that is, the diameter d of the introduction pipe is the same), the diameter D of the container body is made larger than before. The centrifugal separation type oil separator can be reduced in size and weight without reducing the oil separation performance or improving the oil separation performance.

A more preferable range of the ratio (d / D) between the diameter d of the introduction pipe and the diameter D of the container body is as shown in FIG.
0.41 ≦ d / D ≦ 0.43
And a more preferable range is
0.42 ≦ d / D ≦ 0.43
It becomes.

  Although it is considered that the separation efficiency is improved as the height dimension H of the container body 1 is larger, the separation efficiency is almost improved even if the lower end of the cylindrical portion 1a of the container body 1 is extended downward from the lower end portion of the outlet pipe 3. It turns out that it does not improve. This is because even if the cylindrical portion 1c is extended downward from the lower end of the outlet tube 3, the centrifugal separation action by the swirling flow is effective up to the lower end portion of the outlet tube 3, and the cylindrical portion 1c is made longer than this. It is also considered that the swirling refrigerant gas flows into the outlet pipe from the lower end position of the outlet pipe 3. Therefore, in order to reduce the size of the oil separator, the lower end position in the container main body 1 of the outlet pipe 3 and the upper end position of the tapered portion 1c at the lower portion of the container main body should be substantially the same position in the height direction. preferable.

  According to the present embodiment, as described above, since the diameter D of the container body is smaller than the conventional one, the height H of the container body may be set to 5 times or more, so the diameter D of the container body. Therefore, the height H of the container body can be reduced. Even if the height H of the container body is set to 5 times the diameter D of the container body, the lower end position of the outlet tube 3 and the upper end position of the lower tapered portion 1c of the container body are substantially the same position in the height direction. This can prevent the oil separation performance from being lowered.

  The diameter d of the introduction pipe 2 is usually formed to be about 10 to 20% larger than the diameter of the refrigerant pipe from the compressor 10 to the introduction pipe 2. Therefore, even if the diameter d of the introduction pipe 2 is reduced by about 10 to 20%, the fluid loss does not increase. Since the flow velocity increases as the diameter d of the introduction tube 2 decreases, the centrifugal action can be improved. Therefore, when the diameter d of the introduction pipe 2 is configured to be about 1 to 1.1 times the diameter of the refrigerant pipe from the compressor 10 to the introduction pipe 2, the oil separation efficiency can be further improved and the diameter D of the container body. In addition, the height H can be further reduced.

  In the present embodiment, the diameter of the outlet pipe 3 is made equal to the diameter of the refrigerant pipe from the compressor 10 to the introduction pipe 2 and is smaller than the diameter d of the introduction pipe 2. This makes it difficult for the oil separated in the oil separator to be mixed again into the refrigerant gas discharged from the outlet pipe 3, which is effective in improving the separation efficiency. Further, since the diameter of the outlet pipe is made equal to the diameter of the refrigerant pipe from the compressor to the inlet pipe, the pressure loss does not increase.

In the present embodiment, high-pressure refrigerants such as R410A, R32, and CO ₂ are used as the refrigerant in the refrigeration cycle shown in FIG. Further, the diameter d of the introduction pipe 2 is smaller than the diameter φ (see FIG. 3) of the refrigerant pipe on the gas side connecting the outdoor unit and the indoor unit of the air conditioner.
d / φ = 0.75-1.0
By determining the diameter d of the introduction pipe within the range, the increase in pressure loss of the entire refrigeration cycle is suppressed, and the oil separation performance is maintained or improved, and the centrifugal oil separator is reduced in size and weight. Can be achieved.

  FIG. 5 is a horizontal sectional view of the centrifugal oil separator when the maximum oil separation efficiency (d / D) is 0.428 (42.8%) in the diagram shown in FIG. 4 (FIG. 1). It is a figure equivalent to the AA cross section of. In this example, the outer peripheral surface 2a of the distal end portion of the introduction tube 2 formed in a tapered shape along the inner surface of the container is disposed so as to contact the inner wall surface of the cylindrical portion of the container body 1 in the tangential direction. . In addition, the outer peripheral surface 2b of the introduction pipe 2 on the center side of the container body 1 is close to the center line c of the container body 1, but the center line c is not exceeded. As a result, a part of the refrigerant gas flowing out from the inlet pipe 2 collides with the outlet pipe 3 but becomes a turbulent flow along the inner wall surface of the container body 1 with almost no turbulent flow. As the diameter D of the container body 1 is smaller than the conventional one, the centrifugal force is increased, and the oil separation efficiency can be improved.

  As described above, according to this embodiment, it is possible to obtain a centrifugal oil separator that has an oil separation efficiency equal to or higher than that of the conventional one and can be reduced in size and weight. Further, the material cost can be reduced by making the centrifugal oil separator smaller, and the centrifugal separator can be manufactured at a low cost. Furthermore, by applying this centrifugal oil separator to an outdoor unit of an air conditioner, it is possible to reduce the size and cost of the outdoor unit.

1: Container body (1a: cylindrical portion, 1b: upper taper portion, 1c: lower taper portion, 2: introduction pipe)
2 Introducing pipe (2a: outer peripheral surface of the tip of the introducing pipe, 2b: outer peripheral surface of the introducing pipe at the center side of the container body)
3 Outlet pipe 4 Drain pipe (oil return pipe)
5 Outdoor unit 6 Indoor unit 7 Gas side refrigerant piping (local refrigerant piping)
8 Liquid side refrigerant piping (local refrigerant piping)
DESCRIPTION OF SYMBOLS 10 Compressor 11 Four-way valve 12 Outdoor heat exchanger 13 Outdoor expansion valve 17 Gas-liquid separator 24 Throttle mechanism 25 Indoor heat exchanger 26 Indoor expansion valve 100 Oil separator.

Claims (10)

A container body having a cylindrical portion;
An introduction pipe connected to a tangential direction of an inner wall surface of the cylindrical portion at an upper portion of the cylindrical portion of the container body;
A lead-out pipe connected to the upper part of the container body so as to be coaxial with the container body;
In the centrifugal oil separator provided with a discharge pipe connected to the lower part of the container body,
When the diameter of the introduction pipe is d and the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
A centrifugal oil separator characterized by being configured as follows. A container body having a cylindrical portion, and a tapered portion formed integrally with the upper and lower portions of the cylindrical portion;
An introduction pipe connected in the tangential direction of the inner wall surface of the cylindrical part at the upper part of the cylindrical part;
A lead-out pipe connected to the upper part of the container body so as to be coaxial with the container body;
In the centrifugal oil separator provided with a discharge pipe connected to the lower part of the container body,
When the diameter of the introduction pipe is d and the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
And a bottom end position in the container body of the outlet pipe and a top end position of the tapered portion at the bottom of the container body are substantially the same in the height direction. vessel. In Claim 1 or 2, when the height of the container body is H,
H ≧ 5D
A centrifugal oil separator characterized by being configured as follows. In any one of Claims 1-3, when the diameter of the said introduction pipe is set to d and the diameter of the cylindrical part of the said container main body is set to D,
0.41 ≦ d / D ≦ 0.43
A centrifugal oil separator characterized by being configured as follows. In any one of Claims 1-3, when the diameter of the said introduction pipe is set to d and the diameter of the cylindrical part of the said container main body is set to D,
0.42 ≦ d / D ≦ 0.43
A centrifugal oil separator characterized by being configured as follows.   The centrifugal separation type according to any one of claims 1 to 5, wherein an outer peripheral surface of the leading end of the introduction tube is disposed so as to be in tangential contact with an inner wall surface of a cylindrical portion of the container body. Oil separator.   7. The centrifugal oil separator according to claim 1, wherein a diameter of the outlet pipe 3 is smaller than a diameter d of the introduction pipe. In an outdoor unit of an air conditioner including a compressor, an oil separator, an outdoor heat exchanger, and an outdoor expansion valve,
The oil separator is a centrifugal oil separator that is provided on the discharge side of the compressor and that centrifuges refrigeration oil from the discharged refrigerant gas and returns it to the suction side of the compressor. The separator
A container body having a cylindrical portion;
An introduction pipe connected to a tangential direction of an inner wall surface of the cylindrical portion at an upper portion of the cylindrical portion of the container main body, and for allowing refrigerant gas discharged from the compressor to flow into the container main body;
A lead-out pipe for allowing the refrigerant gas separated from the container main body to be inserted into and connected to the upper part of the container main body so as to be coaxial with the container main body and outflowing the refrigerant gas from the container main body;
An oil return pipe connected to the lower part of the container body for returning the refrigeration oil separated from the refrigerant gas in the container body to the compressor;
When the diameter of the introduction pipe is d and the diameter of the cylindrical portion of the container body is D,
0.40 ≦ d / D ≦ 0.44
The outdoor unit of the air conditioner characterized by being comprised. According to claim 8, wherein the refrigerant is an outdoor unit of an air conditioner which is a high-pressure refrigerant such as R410A, R32, CO _2. In Claim 8 or 9, when the diameter of the refrigerant pipe on the gas side connecting the outdoor unit and the indoor unit of the air conditioner is φ, the diameter d of the introduction pipe is
d / φ = 0.75-1.0
The outdoor unit of the air conditioner characterized by being comprised.

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