JPH0320707Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil separator used in a refrigeration system.

(Prior Art) Generally, in a refrigeration system, the compressor and the refrigeration system are used to prevent refrigeration oil from entering the evaporator and impeding the heat transfer effect, or to maintain the required amount of oil in the crankcase. A predetermined oil separator is provided between the compressor and the condenser to separate and recover refrigerating machine oil in the refrigerant gas discharged from the discharge pipe of the compressor.

Conventionally, such oil separators are
For example, as shown in Figure 3, a filter-type oil separator such as a demister is often used (see Figure 7.4 on page 363 of the 4th edition basic edition of the New Refrigeration and Air Conditioning Handbook published by the Japan Refrigeration Association).

That is, in FIG. 3, reference numeral 31 is a drum-shaped hollow shell that constitutes the main body of the oil separator, and the shell 31 has a refrigerant gas outlet 32 at its upper end and an oil outlet at its lower end. 33 are formed respectively. The inside of the shell 31 is partitioned into two chambers, a first chamber 35 on the upper side and a second chamber 36 on the lower side, by a filter member 34 such as a wire demister located above the central part, The first chamber 35 on the upper side and the second chamber 3 on the lower side
A refrigerant gas inlet 37 is formed on the side of the second chamber 36 on the lower side. A refrigerant gas discharge pipe 38 on the compressor side of the refrigeration system is connected thereto.

Therefore, the refrigerant gas in the refrigerant gas discharge pipe 38 flows into the shell 3 through the refrigerant gas inlet 37.
After being introduced into the second chamber 36 of the refrigerant gas 1, the refrigerant gas flows into the upper first chamber 35 through the interfilament space of the filter member 34, and further flows out through the refrigerant gas outlet 32 toward the evaporator. During the flow process, oil particles contained in the refrigerant gas are collected and separated by the linear portions of the filter member 34. The collected and separated oil drips downward, is taken out from the oil outlet 33, and is returned, for example, to the crankcase of the compressor.

(Problems to be Solved by the Invention) However, in such a filter-type oil separator such as a demister, clogging is likely to occur in the filter member portion, and the pressure loss is also high. On the other hand, when the amount of oil coming up in the compressor is small and the oil particles in the refrigerant gas are small and their amount is small, the collection efficiency of the filter member is low, and the oil separation efficiency depends on the amount of oil coming up in the compressor. There were problems such as discrepancies. In particular, in order to increase the separation efficiency in a region where the amount of oil coming up is small, it is necessary to make the filter member high-density, but if this is done, the clogging becomes more likely to occur. At the same time, the pressure loss will also be much greater.

(Means for Solving the Problems) The present invention was made for the purpose of improving the above problems, and as illustrated in FIG. A refrigerant gas inlet portion 6 and a refrigerant gas outlet portion 2 are formed above the refrigerant gas inlet portion 6 and a refrigerant gas outlet portion 2, and a filter member 4 for oil separation is interposed between the refrigerant gas inlet portion 6 and the refrigerant gas outlet portion 2. In the oil separator,
The refrigerant gas inlet part 6 or the outlet part 2 is connected to the large diameter pipe 13 located on the upstream side in the refrigerant gas flow direction and the large diameter pipe 1 located on the downstream side in the refrigerant flow direction.
3 and a small diameter pipe 14 inserted for a predetermined length while maintaining a predetermined distance between the opposing ends of the large diameter pipe 13, and at the end position in the refrigerant flow direction at the insertion part of the large diameter pipe 13 with the small diameter pipe 14. An oil drain hole 19 is formed therein.

(Function) According to the above means, the refrigerant gas inlet or outlet of the oil separator has a double pipe structure in which a large diameter pipe and a small diameter pipe are fitted with a predetermined distance,
In addition to the oil separation effect by the filter member, the annular flow of refrigerant gas generated on the large diameter pipe side of the double pipe section causes the refrigerant gas to be biased toward the inner wall surface of the large diameter pipe and adhere to the inner wall surface of the large diameter pipe. Since the oil flowing toward the downstream small-diameter pipe can be separated and extracted at the fitting portion, the oil separation effect is further improved.

Furthermore, unlike the case of filtration using a filter member such as a demister, oil separation in the double pipe section can always be performed with a constant separation efficiency, regardless of the amount of oil in the refrigerant gas. Therefore, it becomes possible to sufficiently compensate for the poor oil separation efficiency of the filter member in the range of low oil flow rate, and it is possible to greatly improve the oil separation efficiency as a whole by combining the two. It becomes possible.

(Embodiment) FIG. 1 shows an oil separator for a refrigeration system according to an embodiment of the present invention.

First, in FIG. 1, reference numeral 1 denotes a drum-shaped shell that constitutes the main body of the oil separator.The upper end of this shell has a refrigerant gas outlet 2, and the lower end has an oil outlet 3. Refrigerant gas inlet portions 6 are formed on each side. Between the refrigerant gas inlet part 6 and the refrigerant gas outlet part 2, a wire demister (filter in the scope of the utility model registration claims) is located in the upper part of the shell 1 and is fitted and fixed approximately horizontally. (corresponding to a member) 4 is interposed, and the refrigerant gas introduced into the shell 1 from the refrigerant gas inlet portion 6 passes through the wire demister 4 and flows from the refrigerant gas outlet portion 2 to the condenser side (not shown). It's starting to leak out.

On the other hand, the refrigerant gas inlet 6 is held by passing through a sleeve-shaped boss member 7 whose base side is fitted into a fitting hole formed in the side wall 1a of the shell 1 and fixed. While the side opening 8 is inserted into the shell 1, the other end side opening is inserted into the shell 1.
A large-diameter pipe 13 located on the upstream side in the refrigerant gas distribution direction that projects outside and is connected to the compressor-side refrigerant gas discharge pipe 10; It consists of a small diameter pipe 14 located on the downstream side in the refrigerant gas flow direction, which is fitted for a predetermined length on one side, and a mesh member 15 is mounted on the end of the small diameter pipe 14 on the non-fitting side. .

The tube wall portion 16 of the portion of the large-diameter tube 13 fitted into the shell 1 is formed with, for example, a spiral groove, and a centrifugal force in the swirling direction is applied to the refrigerant gas flow flowing inside the tube. It's starting to work. The end of the large-diameter pipe 13 on the side where the small-diameter pipe 14 is fitted is joined and sealed to the outer peripheral surface of the pipe wall of the small-diameter pipe 14, and the lower part near the joint (the end in the refrigerant gas flow direction) is sealed. An oil drain hole 19 is formed at the position).

Therefore, according to the above configuration, the refrigerant gas discharged from the compressor first passes through the refrigerant gas discharge pipe 10, the large diameter pipe 13 for introducing refrigerant gas, and then the small diameter pipe 14.
be introduced within. When the refrigerant gas is introduced into the small diameter pipe 14, a first stage of separation of oil in the refrigerant gas is performed.

That is, the shell inner tube wall 16 of the large-diameter pipe 13 for introducing the refrigerant gas has a spiral shape in the refrigerant gas flow direction as described above, so that the refrigerant gas flow inside the large-diameter pipe 13 is The flow effectively becomes an annular flow, and centrifugal force acts in the direction of the pipe wall. This centrifugal force acts most strongly on oil, which has a high specific gravity, in the refrigerant gas. As a result, the oil gradually collects on the inner circumferential wall surface of the helical groove of the large diameter pipe 13 and flows downstream, eventually collecting near the joint surface of the fitting part with the small diameter pipe 14 and below. It becomes like this. Since an oil drain hole 19 is formed at the bottom of the collecting section, the oil remaining in the collecting section drips downward into the shell 1 through the oil drain hole 19 and is taken out from the oil outlet 3. For example, it is returned into the crankcase of the compressor via an oil return path. In this case, the oil separation action in the first stage is performed by causing the refrigerant gas to flow in a spiral manner as described above, thereby effectively applying centrifugal force to the oil with a high specific gravity in the refrigerant gas, and removing only the oil. Since the oil is extracted, it is possible to always increase the separation efficiency to a certain level regardless of the amount of oil coming up in the compressor.

Next, the refrigerant gas that has first completed the oil separation process in the first stage as described above passes through the small diameter pipe 14 and is further filtered out by the mesh member 15 at its outlet so that the oil droplets in the refrigerant gas are removed. It is collected and separated in two stages.

The refrigerant gas from which the oil has been separated in the second stage is then led to the inner space of the shell 1, and then further passes through the wire demister 4 and flows out from the refrigerant gas outlet 2. Then, oil separation is performed in the wire demister 4 portion as a third stage. That is, the wire demister 4
is constructed by combining a plurality of wire filaments at high density, and by passing the refrigerant gas through the filament space, it collects and separates mist-like oil molecules contained in the refrigerant gas. As a result, the refrigerant gas from which the oil has finally been separated has a wide range of oil components from the initially contained oil droplets to mist-like oil molecules removed.

The oil separation efficiency characteristics at each of the above-mentioned stages 1 to 3 and the oil separation efficiency characteristics according to their combination are shown in FIG. 2. It can be seen that by combining the oil separation actions of the stages, it becomes possible to increase the oil separation efficiency to nearly 100% in all ranges from high to low oil flow rates of the compressor.

In addition, in the above embodiment, in addition to the oil separation effect by the double pipe structure as the first stage, oil separation by the mesh member 15 as the second stage and oil separation by the wire demister 4 as the third stage. Although three types of separation actions are combined, a sufficiently high oil separation efficiency can also be achieved by the oil separation action using only the double pipe and wire demister 4 without providing the mesh member 15 of the second stage.

In addition, the shell 1 inner tube wall portion 16 of the large diameter tube 13 is
It is not necessarily necessary to have a spiral groove shape; if the flow velocity is above a predetermined value, an annular flow is generally formed even with a straight pipe wall, so that a sufficient separation effect can be obtained.

(Effect of the invention) As explained above, the present invention forms an oil outlet at the bottom of the shell, and above the oil outlet, a refrigerant gas inlet and a refrigerant gas outlet. In an oil separator in which a filter member for oil separation is interposed between the refrigerant gas inlet or the refrigerant gas outlet, the refrigerant gas inlet or the outlet is connected to a large-diameter filter located on the upstream side in the flow direction of the refrigerant gas. and a small-diameter pipe located downstream in the refrigerant flow direction and inserted into opposite ends of the large-diameter pipe for a predetermined distance with a predetermined distance, the small-diameter pipe of the large-diameter pipe. It is characterized in that an oil drain hole is formed at the end position in the refrigerant flow direction in the fitting part with the refrigerant.

Therefore, according to the present invention, the refrigerant gas inlet or outlet of the oil separator has a double pipe structure in which a large diameter pipe and a small diameter pipe are fitted with a predetermined distance between them. In addition to the oil separation effect of the parts,
Furthermore, due to the annular flow of refrigerant gas generated on the large diameter pipe side of the double pipe section, oil is biased toward the inner wall surface of the large diameter pipe, adheres to the inner wall surface of the large diameter pipe, and flows toward the downstream small diameter pipe. Since oil can be separated and extracted at the fitting portion, the oil separation effect is further improved.

Furthermore, unlike the case of filtration using a filter member such as a demister, oil separation in the double pipe section can always be performed with a constant separation efficiency, regardless of the amount of oil in the refrigerant gas. Therefore, it becomes possible to sufficiently compensate for the poor oil separation efficiency of the filter member in the range of low oil flow rate, and it is possible to greatly improve the oil separation efficiency as a whole by combining the two. It becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an oil separator according to an embodiment of the present invention, Fig. 2 is a graph showing the oil separation efficiency of the oil separator of the above embodiment, and Fig. 3 is a graph of a conventional oil separator. FIG. 1... Shell, 2... Refrigerant gas outlet, 3...
...Oil outlet, 4...Wire demister, 6...
Refrigerant gas inlet portion, 13...large diameter pipe, 14...small diameter pipe, 19...oil drain hole.

Claims (1)

[Scope of utility model registration request] An oil outlet 3 is provided at the bottom of the shell 1, and a refrigerant gas inlet 6 and a refrigerant gas outlet 2 are provided above it.
In the oil separator in which a filter member 4 for oil separation is interposed between the refrigerant gas inlet port 6 and the refrigerant gas outlet port 2, the refrigerant gas inlet port 6 or the refrigerant gas outlet port 2 is provided. The large diameter pipe 13 is located on the upstream side in the refrigerant gas flow direction, and the large diameter pipe 13 is located on the downstream side in the refrigerant flow direction.
A small-diameter pipe 14 is inserted for a predetermined length into opposing ends of the large-diameter pipe 13 while maintaining a predetermined distance, and oil is provided at the end position in the refrigerant flow direction at the insertion portion of the large-diameter pipe 13 with the small-diameter pipe 14. An oil separator characterized in that a extraction hole 19 is formed.