JP3392621B2 - Oil separator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil separator for separating refrigerating machine oil from a refrigerant mixed with refrigerating machine oil.

[0002]

2. Description of the Related Art Generally, in a refrigerant circuit for circulating a refrigerant such as an air conditioner or a refrigerator, an oil separator is provided in order to separate refrigerating machine oil mixed with the refrigerant and return it to a compressor. .

In such a conventional oil separator, as shown in FIGS. 7 and 8, a gas refrigerant compressed by a compressor is introduced from an inlet pipe 50 into a container 51 of the oil separator to mainly separate plate 53. After the gas refrigerant is made to collide with the oil to precipitate the oil, the gas is passed through the passage hole 55 and the swirl hole 57 formed in the separation plate 53 to be guided to the space inside the container, and the outlet pipe 5 extended into the container.
The refrigerant in the inner space of the container is taken in through the opening 59a of 9 and sent out to the refrigerant circuit (condenser).

In the space inside the container, the gas refrigerant that has passed through the separation plate 53 swirls inside the container as shown by the solid arrow in FIG. It is taken into the outlet pipe 59.

The refrigerating machine oil thus separated by the separating plate 53 and the space inside the container is stored in the bottom of the container 51 and returned to the compressor from the oil outlet pipe 61.

On the other hand, conventionally, a refrigerant containing a chlorine group,
So-called HCFC refrigerant was used, and mineral oil was used as the refrigerating machine oil in that case.

However, since the HCFC refrigerant has the potential of depleting the ozone layer above the ground, in recent years, HFC refrigerants having a low chlorine group content have been used for the purpose of environmental protection and the like. In such an HFC refrigerant, an ester oil having compatibility is used as the refrigerating machine oil, but since the ester oil has a low compatibility with the HFC refrigerant, the solubility of the refrigerating machine oil in the refrigerant is higher than that in the mineral oil in the HCFC refrigerant. descend. For this reason, there is a possibility that the amount of oil returned to the compressor after circulating through the refrigerant circuit may be reduced. Therefore, it is necessary that the refrigerant discharged from the compressor is reliably separated by the oil separator, and the refrigerating machine oil is surely returned to the compressor.

[0008]

However, in the above-mentioned conventional oil separator, when the refrigerant flow rate is high, as shown by the broken line in the graph of FIG. 6, the relationship between the refrigerant gas flow rate and the oil separation efficiency. The oil separation efficiency is not sufficient even in the (high flow rate range), but there is a disadvantage that the oil separation efficiency is significantly reduced particularly in the case of the bottom flow rate (low flow rate range).

That is, when the flow rate of the refrigerant is high, the oil separated by the separation plate may be scattered and taken into the opening of the outlet pipe, or the oil separation may not be sufficient in the space inside the container. It is considered that the efficiency is not sufficient. Further, in the case of the bottom flow rate, the downward flow from the passage hole 55 is mainly present in the separation plate, almost no component force in the swirling direction is obtained, and further, due to the static pressure in the container, the passage hole 55 is generated. It is conceivable that the refrigerant that has flowed out of the refrigerant flows into the opening 59a of the outlet pipe as it is, as shown by the alternate long and short dash line in FIGS. Thus, there is a problem that refrigerating machine oil cannot be reliably separated from the refrigerant in the container of the conventional oil separator.

The present invention has been made to solve the above problems, and provides an oil separator capable of reliably separating refrigerating machine oil from a refrigerant not only at a high flow rate but also at a low flow rate. To do.

[0011]

According to a first aspect of the present invention, there is provided an inlet pipe through which a refrigerant mixed with refrigerating machine oil flows into a container, and the inlet pipe is arranged so as to face the inlet pipe, and after the refrigerant collides with the inlet pipe. A separation plate that allows the refrigerant to pass from the passage hole to the space inside the container,
In an oil separator comprising an outlet pipe for taking in the refrigerant in the container space from an opening located in the downward direction of the refrigerant with respect to the separation plate, the separation plate includes an outside of the outlet pipe.
And a cylindrical cover extending beyond the opening of the outlet pipe.
The tubular cover has the passage hole.
Swirl that is inclined with respect to the downflow direction of the refrigerant at a position facing the
It is equipped with a plate.

According to the first aspect of the invention, the refrigerant mixed with the refrigerating machine oil flows into the container from the inlet pipe, and the refrigerant flowing from the inlet pipe collides with the separation plate to deposit oil droplets. Let Since the oil on the separation plate has a cover around the opening of the outlet pipe, the oil is scattered from the separation plate and taken into the outlet pipe even when the flow rate of the refrigerant is not only high but low. To be prevented. On the other hand, although the oil droplets that have not been completely separated are mixed in the refrigerant, the refrigerant is introduced into the space inside the container through the passage holes formed in the separation plate.

[0013]

[0014]

[0015]

[0016]

The refrigerant passing through the passage holes hits the swirl plate inclined in the circumferential direction and flows in the circumferential direction, so that the refrigerant passing through the passage holes can be caused to flow in the swirling direction. As a result, a centrifugal separation action occurs, and the passage distance in the container becomes long, so that the oil component can be more effectively separated from the refrigerant after passing through the separation plate. In addition, the swirl plate serves as a contact surface with the refrigerant to increase the chances of depositing the oil component, thereby increasing the oil separation efficiency.

According to a second aspect of the present invention, an inlet pipe through which a refrigerant mixed with refrigerating machine oil flows into the container, and an inlet pipe that is disposed so as to face the inlet pipe and collides with the refrigerant and then passes the refrigerant through the passage hole to supply the refrigerant to the container. In the oil separator including a separation plate to be passed through the inner space, and an outlet pipe that takes in the refrigerant in the container inner space from an opening located in the downward direction of the refrigerant with respect to the separation plate, in the separation plate, The passage hole is provided with a guide tube that extends beyond the opening of the outlet tube and guides the refrigerant.

In the invention described in claim 2, the refrigerant having passed through the passage hole is guided by the guide tube and introduced into the space inside the container at a position beyond the opening of the outlet tube. Therefore, the separation plate
After passing through, the refrigerant introduced into the container space, sucrose - Tosa - without being incorporated directly into the outlet pipe by Kit,
In addition, since the guide pipe extends beyond the opening of the outlet pipe, the refrigerant that flows down always inverts, so the oil that has a higher density than the refrigerant is reliably separated by the inversion, and the oil separation efficiency is increased. You can In addition, the refrigerant in the space inside the container comes into contact with the guide tube, and oil is likely to be deposited.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a refrigerant circuit diagram of an air conditioner in which an oil separator according to an embodiment of the present invention is used.

First, the refrigerant will be described.

This air conditioner uses an HFC type refrigerant having a small chlorine group as a refrigerant circulating in the refrigerant circuit.
We are working to protect the environment by preventing the ozone layer from being destroyed by chlorine. As such a refrigerant, for example, as a three-component mixed refrigerant, R-134a (tetrafluoroethane) is 52 wt% and R-125 (pentafluoroethane) is 2 wt%.
5 wt%, R-32 (difluoromethane) 23 wt%
There is R-407C mixed in. As the two-component mixed refrigerant, R-32 is 50 wt% and R-125 is 50 wt%.
% Of R-410A or R-32 mixed at 45% by weight,
R-410B mixed with R-125 at 55 wt% is used.

Ester oil (polyol ester) compatible with these HFC refrigerants is used as the refrigerating machine oil to be mixed with the refrigerant, but is more compatible than the conventional HCFC refrigerant and mineral oil. Is small (small solubility). Therefore, when the HFC-based refrigerant and the ester oil are mixed and used, there is a high possibility that they will be trapped (captured) by a refrigerating machine such as a condenser while circulating in the refrigerant circuit. Immediately after that, it is required to surely separate the refrigerating machine oil by the oil separator and return it to the compressor (to secure the oil returning characteristic).

In the refrigerant circuit of the air conditioner shown in FIG. 1, a compressor 1, an oil separator 3, a condenser 5 acting as an outdoor heat exchanger, a capillary tube 7 acting as a pressure reducing device,
An evaporator 9 and an accumulator 11 that act as an indoor heat exchanger are connected in this order by a refrigerant pipe.

In this refrigerant circuit, the refrigerant discharged from the compressor 1 is condensed in the condenser 5, then rapidly depressurized in the capillary tube 7 and evaporated in the evaporator 9 to cool the indoor air. And cool the room.

In the oil separator 3, refrigerating machine oil (ester oil) dissolved in the refrigerant discharged by the compressor 1 is separated, and the separated refrigerating machine oil (hereinafter referred to as "oil") is used as a compressor. Return and send refrigerant to the condenser.

In the oil separator 3, as shown in FIG. 2, an inlet pipe 17 for introducing the refrigerant discharged from the compressor 1 is connected to the top plate 15a of the cylindrical container 15, and the container 15 is connected. In the inside, a separation plate 2 for colliding the refrigerant introduced from the inlet pipe 17 at a position facing the inlet pipe 17 to precipitate oil
1 is fixed. At the bottom of the container, an outlet pipe 19 for leading out the refrigerant after separating the oil is extended from the bottom to the middle of the space A in the container, and the outlet pipe 19 is
A tube having an opening 19a at the upper end surface is inserted from the bottom 15b of the container, and the opening 19a at the upper end surface is arranged at a distance h from the separating plate 21.

Further, an oil return pipe 23 for returning the oil separated in the container and accumulated at the bottom to the compressor 1 is connected to the bottom 15b of the container.

As shown in FIGS. 2 and 3, the separating plate 21 has a cylindrical cover 25 extending downward beyond the opening 19a of the outlet pipe 19 so as to surround the outside of the outlet pipe 19. The opening 19a of the outlet pipe 19 is covered from above.

That is, from the separating plate 21 to the opening 19a of the outlet pipe.
Up to a distance h, the cover 25 is extended with a distance H longer than the distance h, whereby the oil deposited on the separation plate 21 scatters and is taken into the outlet pipe 19 or the separation plate 21. This prevents a short circuit kit in which the refrigerant that has passed through is directly taken into the outlet pipe 19.

A large number of passage holes 27 and swirl holes 29 are formed around the separation plate 21. The passage hole 27 and the swirl hole 29 guide the refrigerant after colliding with the separation plate 21 to the space A in the container. The passage hole 27 is a through hole punched out in a circular shape, and allows the refrigerant introduced above the separation plate 21 to pass downward as it is.

On the other hand, the swirl hole 29 is formed by denting with a press and cutting out one end surface of the swirl hole 29 to form an opening in the circumferential direction, which allows the refrigerant to pass in a swirling direction substantially parallel to the separating plate 21. Is. By forming such a swirl hole 29, a flow in the swirling direction is imparted to the refrigerant that has passed through the separation plate 21, the moving distance of the refrigerant in the container internal space A is lengthened, and the oil separation efficiency is increased by the centrifugal action. Can be increased.

The opening area of the swirl hole 29 is smaller than that of the passage hole in order to obtain a predetermined flow velocity.

Next, the operation of the oil separator will be described.

The refrigerant discharged from the compressor 1 contains a large amount of refrigerating machine oil.
Is introduced into the container 15 of the oil separator 3. The refrigerant flowing from the inlet pipe 19 is in a state in which a droplet of oil is mixed in a gaseous refrigerant, and the refrigerant collides with the separation plate 21 to deposit a part of oil droplets, It is introduced into the space A in the container through the passage hole 27 and the swirl hole 29. The oil droplets deposited on the separation plate 21 drop to the bottom of the container 15.

On the separation plate 21, the oil deposited due to the collision of the refrigerant introduced from the inlet pipe 19 is scattered, but since the opening 19a of the outlet pipe 19 is covered with the cover 25, it is scattered from the separation plate 21. The oil droplets formed are the openings 19a of the outlet pipe.
It is prevented from being taken in from.

Since the oil droplets that cannot be completely separated by the separation plate 21 are mixed in the gaseous refrigerant introduced into the container space A, oil is also removed from the refrigerant in the container space A as follows. To be separated. Here, the flow of the refrigerant in the container space A will be described, but the case where the flow rate of the refrigerant discharged from the compressor is a high flow rate and the case where the flow rate of the refrigerant is a low flow rate will be described separately.

[High Flow Rate] When the flow rate is high, the refrigerant can give a sufficient force in the swirling direction when passing through the swirling hole 29 formed in the separating plate 21. On the other hand, although the refrigerant flows downward from the passage hole 27, the flow in the swirling direction is added to the downward flow to form a combined vector in the flow of the refrigerant, and the refrigerant is swirling in the container while being downward. It will flow in a spiral shape toward.

The coolant which has passed through the separating plate 21 is directly taken into the opening 19a of the outlet pipe because there is the cover 25 extending below the opening 19a of the outlet pipe.
Kit is prevented. Therefore, the refrigerant must always have the opening 19
After flowing below a, it is reversed and the outlet pipe 19 and cover
It is taken in after moving from below to above through 25.

That is, during the flow of the refrigerant gas that swirls and moves up and down, deceleration, direction change, etc. cause oil droplets having a higher density than the refrigerant gas to separate from the refrigerant gas due to the difference in inertial force, and Mechanical separation of the drops takes place.

In addition, the movement distance of the refrigerant becomes long due to the swirling and the vertical movement, and the separation of the oil droplets easily proceeds.

Further, in the container space A, the refrigerant covers the cover-2.
Since there is an opportunity to come into contact with No. 5, precipitation of oil droplets can be promoted.

[Bottom flow rate] When the flow rate is low, since the opening area of the swirl hole 29 is small, there is almost no refrigerant flow from here, and most of the refrigerant flows downward through the passage hole 27. It becomes a flow and almost no turning occurs. In this case, since there is the cover 25, there is no occurrence of a short-circuit kit in which the refrigerant directly flows into the opening of the outlet pipe, and the refrigerant that has passed through the passage hole as shown by the one-dot chain line in FIG. The flow-down distance that flows downward is increased, and the movement distance (flow-down distance) in the space A inside the container is increased, so that the separation of oil droplets easily proceeds. Next, since the refrigerant rises toward the opening 19a of the outlet pipe 19 after flowing down, an abrupt direction change occurs here, and the oil droplets having a high density are separated by the difference in inertial force.

As described above, in this embodiment, high oil separation efficiency can be obtained in both the high flow rate region and the bottom flow rate region.

As described above, by increasing the effect of the oil separator, particularly when an inverter-driven compressor is used from the viewpoint of capacity control, the accumulated oil in the refrigerant circuit under long pipe and low speed operation conditions is used. It is not necessary to forcibly operate the oil return mode to return the oil to the compressor.

Here, the effects of the present embodiment described above are
This will be described with reference to FIG. FIG. 6 is a graph in which the horizontal axis represents the flow rate of the refrigerant gas and the vertical axis represents the oil separation efficiency, and shows the results of experiments in comparison with the related art.

As is clear from the graph of FIG. 6, in the present embodiment (present invention) shown by the solid line in FIG. 6, compared with the conventional case shown by the broken line, in the bottom flow rate range and the high flow rate range, It was possible to obtain higher oil separation efficiency. In particular,
In the bottom flow rate region, almost no oil could be conventionally separated, but in the present embodiment, sufficient oil separation efficiency could be obtained even in the bottom flow rate region.

Next, another embodiment of the present invention will be described. In the embodiment described below, only the configuration of the separation plate will be described, but in the configuration of the separation plate, the same parts as those in the above-mentioned embodiment are denoted by the same reference numerals and detailed description thereof will be omitted. To do.

FIG. 4 shows a second embodiment, which is different from the separating plate 21 in the first embodiment described above in that only the through holes 27 are formed without forming the swirling holes. The swirl plate 31 that swirls the downstream side of the passage hole 27 is arranged on the downstream side of the passage hole 27. This swivel plate 3
The reference numeral 1 designates a flat plate which is obliquely fixed to the periphery of the cover 25 with respect to the flow of the refrigerant passing through the passage hole 27.

According to the second embodiment, the same effect as that of the first embodiment described above can be obtained, and it is not necessary to make a turning hole in the separating plate 21, so that the passage hole 2 can be obtained.
Since only 5 needs to be punched into a disk, the separation plate can be easily manufactured.

Further, even in the case of the bottom flow rate, the swirl flow can be generated by the swirl plate 31, so that the oil separation efficiency in the bottom flow rate range can be further enhanced.

FIG. 5 shows a third embodiment, which is different from the first embodiment in that a cover for covering the outlet pipe is not provided and the same as the above-mentioned second embodiment. In addition, only the through holes 27 are formed in the separation plate 21,
A guide pipe 33 is arranged on the downstream side of all the passage holes 27 to extend the refrigerant passing through the passage holes 27 below the opening of the outlet pipe. It is sufficient that the guide tube extends longer than the distance h, like the cover 25 in the first embodiment. Further, in the present embodiment, a curved pipe (guide pipe) 33 is used as the guide pipe 33 to give a swirl.

In the third embodiment, it is guided by the guide pipe 33 and introduced into the space A in the container at a position beyond the opening 19a of the outlet pipe. Therefore, similarly to the first embodiment in which the cover 25 that covers the opening 19a of the outlet pipe is provided, after passing through the separation plate 21, the oil scattered on the separation plate 21 and the refrigerant that has passed through the separation plate are not exposed. -It is not directly incorporated into the outlet pipe by the Tosa kit.

Moreover, since the bent tube is used as the guide tube 33, the refrigerant passing through the passage hole 27 can be swirled. Also in the third embodiment, high separation efficiency can be obtained as in the first embodiment described above.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in the embodiment shown in FIG.
Only the passage hole may be formed without providing the passage hole and the swirl hole in the separation plate. In this case, a swirling flow cannot be obtained in the case of a large flow rate in the internal space A of the container, but the effect of only the cover, that is, the invasion of oil droplets scattered from the separation plate and the prevention of the short server kit can be prevented. In addition, it is possible to increase the flow-down distance and to separate the oil droplets by abrupt direction change in the case of the bottom flow rate.

In the second embodiment shown in FIG. 4, the swivel plate 31 is not limited to a flat plate, and a curved plate whose plate surface forms an arc may be used. In this case, the swirling flow can be increased.

Further, in the third embodiment shown in FIG.
A hole may be formed in the tube body of the guide tube to give a swirling flow. In this case, the hole formed in the tube body needs to be formed below the distance h.

Further, the guide tube 33 is not limited to a bent tube, and a similar effect can be obtained even if a straight tube is obliquely attached.

[0061]

[0062]

[0063]

Effects of the Invention According to the invention described in claim 1, oil separation
In the separator plate of the container, the opening of the outlet pipe is provided around the outlet pipe.
Since it has a cylindrical cover that extends beyond,
The flow of the refrigerant passing through the holes goes directly to the opening of the outlet pipe.
Can not be directly attached to the outlet pipe by the shorts kit.
Oil that was not taken in and that was scattered from the separation plate
Can be prevented from entering the outlet pipe. Furthermore, since the refrigerant that has passed through the passage holes hits the swivel plate that is inclined toward the circumferential direction and flows in the circumferential direction, the refrigerant that has passed through the passage holes is
Flow in the swirling direction can be generated . By this
As a result, a centrifugal action occurs, and the passage distance in the container becomes long, so that the oil component can be more effectively separated from the refrigerant after passing through the separation plate. In addition, the swirl plate serves as a contact surface with the refrigerant to increase the chances of depositing the oil component, thereby increasing the oil separation efficiency.

According to the invention as set forth in claim 2, since the separation plate is provided with the guide tube extending in the passage hole for passing the refrigerant beyond the opening of the outlet pipe , the separation plate scatters from the separation plate. Oil can be prevented from entering the outlet pipe, and the refrigerant after passing through the separation plate is not directly taken into the outlet pipe by the short-circuit kit, so that the flow of the refrigerant is necessarily reversed, so In addition, oil with high density can be reliably separated and the efficiency of oil separation can be increased. Furthermore,
Oil tends to deposit on the guide tube.

[0065]

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner including an oil separator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the oil separator shown in FIG.

FIG. 3 is a perspective view showing a separation plate and an outlet pipe shown in FIG. 2 in an extracted manner.

FIG. 4 is a perspective view showing a separation plate and an outlet pipe according to a second embodiment of the present invention in an extracted state.

FIG. 5 is a perspective view showing a separation plate and an outlet pipe according to a third embodiment of the present invention in an extracted state.

FIG. 6 is a graph showing the relationship between the refrigerant gas flow rate and the oil separation efficiency according to the present invention in comparison with the related art.

FIG. 7 is a sectional view of a conventional oil separator.

FIG. 8 is a plan view showing a conventional separation plate.

[Explanation of symbols]

3 oil separator 17 Inlet pipe 19 outlet pipe 21 Separation plate 25 covers 27 passage hole 29 swirl hole 31 swivel plate 33 Bent pipe (guide pipe)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Masuda 2-5-5 Keihan Hon-dori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (56) Bibliographic references Sho 62-198465 (JP, U) 52-130256 (JP, U) Actual opening 55-133178 (JP, U) Actual opening 61-13271 (JP, U) Actual opening Flat 1-83412 (JP, U) Actual opening Sho 62-183561 (JP , U) Actual exploitation Sho 53-84164 (JP, U) Actual exploitation Sho 48-113045 (JP, U) Japanese Patent Publication No. 47-2949 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) F25B 43/02 F25B 1/00 387 F25B 43/00

Claims (2)

(57) [Claims] 1. An inlet pipe through which a refrigerant mixed with refrigerating machine oil flows into a container, and a separation plate which is disposed so as to face the inlet pipe and which allows the refrigerant to pass through a passage hole into a space in the container after the refrigerant collides. And an oil separator having an outlet pipe that takes in the refrigerant in the space in the container from an opening located in the downward direction of the refrigerant with respect to the separation plate, in the separation plate, outside the outlet pipe, The outlet pipe is provided with a tubular cover extending beyond the opening, and the tubular cover is provided with a swirl plate that is inclined with respect to the flow-down direction of the refrigerant at a position facing the passage hole. An oil separator characterized by comprising. 2. An inlet pipe through which a refrigerant mixed with refrigerating machine oil flows into a container, and a separation plate which is arranged so as to face the inlet pipe and which allows the refrigerant to pass through the passage hole to the space inside the container after the refrigerant collides. And an outlet pipe for taking in the refrigerant in the space in the container from an opening located in the downward direction of the refrigerant with respect to the separation plate, wherein the separation plate has the outlet pipe in the passage hole. Is provided with a guide tube that extends beyond the opening of the and that guides the refrigerant.