JPH07107468B2 - Refrigeration equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refrigerating apparatus using a mixed refrigerant.

2. Description of the Related Art A refrigeration system using a mixed refrigerant can perform capacity control and performance improvement by varying the composition ratio of the refrigerant circulating inside the cycle.

Conventionally, a rectification separation method utilizing a difference in boiling point has been used as a method for varying the composition of the refrigerant circulating in the cycle of a refrigeration system using a non-azeotropic mixed refrigerant (for example, Japanese Patent Laid-Open No. 61- No. 101757).

An example of the refrigerating apparatus using the rectification separation system will be described below with reference to FIGS. 5 and 6.

FIG. 5 is a refrigeration cycle diagram showing a conventional example, and FIG. 6 is a sectional view of a rectification column for changing the composition ratio of the non-azeotropic mixed refrigerant.

In FIG. 5, 1 is a compressor, 2 is a condenser, 3 is a main expansion device, and 4 is an evaporator, which are annularly connected to form a main circuit. On the other hand, the outlet of the condenser 2 and the inlet of the rectification tower 6 are piped.
The heater 5 is connected to the pipe 10 by heat exchange. Further, the lower outlet of the rectification column 6 and the inlet of the evaporator 4 of the main circuit are connected via the auxiliary expansion device 7 by the pipes 11 and 12. Further, a cooler 8 and a reservoir 95 are provided above the rectification column 6, and the reservoir 9 is connected to the rectification column 6 in an annular shape by pipes 13 and 14. Also, cooler 8 and piping
13 and 13 are connected by heat exchange. Here, as the heat source of the heater 5 and the cooler 8, the discharge gas and the suction gas of the compressor 1 are used. As the refrigerant, a non-azeotropic mixed refrigerant composed of two kinds of refrigerants having different boiling points is used.

In FIG. 6, 601 is the main body of the rectification tower 6, 602 is a packing material,
603 and 604 are filler holders.

The operation of the refrigerating apparatus configured as described above will be described below.

First, the case where rectification separation is not performed will be described.

A part of the high-pressure liquid refrigerant discharged from the condenser 2 is branched by the pipe 10. At this time, if the valve opening of the sub-throttle device 7 is increased, the flow rate of the branch refrigerant branched to the pipe 10 is increased, and the heating of the heater 5 is insufficient, so that steam is not generated and liquid is discharged from the lower inlet of the rectification column 6. Refrigerant flows in. As a result, the rectification action does not proceed, the liquid refrigerant rises inside the rectification column 6, enters the reservoir 9 through the pipe 13, and returns to the rectification line 6 again through the pipe 14. Then, the pressure is reduced by the sub expansion device 7 and merges with the main circuit side refrigerant.

In this way, the composition ratio of the low boiling point inside the reservoir 9 does not increase, so that the composition ratio of the main circuit becomes equal to the refrigerant filling ratio.

Next, the case of performing rectification separation will be described.

When the valve opening of the sub-throttle device 7 is reduced from the above state, the flow rate of the branched refrigerant decreases, and the liquid refrigerant branched from the condenser 2 is heated by the heater 5 and partially vaporized. It flows in from the lower entrance of the distillation column 6. This gas component rises in the clearance of the packing material 602 in the rectification column 6, enters the cooler 8 through the pipe 13 from the upper outlet, is cooled and liquefied, and enters the reservoir 9.
A drop A is provided in advance between the reservoir 9 and the return pipe 14 of the rectification tower 6, and due to the drop A, a part of the liquid refrigerant from the reservoir 9 is returned to the rectification tower 6 through the pipe 14 and the packing material is filled. It goes down the clearance of 602 and makes vapor-liquid contact with the steam that rises midway, making rectification by heat exchange and mass transfer,
A refrigerant having a large amount of low boiling point components is stored in the reservoir 9, and a refrigerant having a small amount of low boiling point components flows into the circuit from the lower portion of the rectification column 6 through the pipe 11, the sub expansion device 7, and the pipe 12.

Therefore, the low boiling point component ratio of the main circuit decreases and the high boiling point component ratio increases.

As described above, by controlling the valve opening of the auxiliary expansion device 7, the amount of steam generated is adjusted to perform rectification separation, and by changing the composition ratio of the refrigerant stored in the reservoir 9,
The composition ratio of the main circuit refrigerant can be made variable.

However, the above configuration has the following problems.

First of all, if the rectification tower is installed tilted, the refrigerant vapor and the liquid refrigerant rise and fall on the wall surface of the tower, making it difficult for gas-liquid contact to occur, heat exchange and mass transfer are reduced, and rectification separation performance is also reduced. To do. Therefore, it is necessary to install the rectification column vertically.

Secondly, in the height relationship between the upper return port of the rectification tower and the reservoir, a certain drop A shown in FIG. 6 is set so that the liquid stored in the reservoir returns to the rectification tower due to potential energy. is necessary.

Thirdly, in order to carry out rectification separation, it is necessary to carry out heating and the like and to inject the refrigerant vapor from the lower part of the rectification column.

Fourthly, in order to improve the rectification separation performance, it is necessary to put a packing material inside the column to increase the height and the number of theoretical plates.

Fifth, the flow rate of the branched refrigerant during the rectification separation depends on the capabilities of the heater and the cooler. If the flow rate is too large, the rectification action does not proceed as described above, so the flow rate must be reduced.
Therefore, rectification separation requires time.

Since rectification separation utilizes the difference in boiling points, it cannot be used for azeotropic mixed refrigerants having similar boiling points.

As described above, there are many restrictions on mounting and installation, and there are problems that the device is large and complicated.

In order to solve the above problems, a refrigeration system using a refrigerant separation device having a functional film that facilitates the permeation of a specific type of refrigerant has been devised.

First, the experimental results that show that it is possible to use a functional membrane for refrigerant separation will be described.

FIG. 4 shows an embodiment of a refrigerant separator (hereinafter referred to as a separator) using a functional film.

In the figure, the separator main body 102 is partitioned into a high pressure side space a and a low pressure side space b by a mesh-shaped holder 104, and the functional film 103 is installed on the high pressure side of the holder 104. Further, the separator main body 102 has a high pressure refrigerant inlet pipe 105, an outlet pipe 106, and a permeated refrigerant outlet pipe 10.
7 is provided.

In the separator configured as described above, a benzene solution of dimethyl silicone was spread on water as a functional film to form an ultra-thin film, and then a thin film formed by transfer film formation on a polypropylene porous chamber film (Ceraneys Co., Ltd .: Jura Guard) was prepared. The case of separating a mixed refrigerant of R-22 and R-13B1 used as a molecular composite film will be described.

The mixed refrigerant pressurized by the compressor or the like is sent from the inlet pipe 105 to the high pressure side space a in the separator body 102. Here, due to the pressure difference between the high pressure side space a and the low pressure side space b, a part of the refrigerant permeates into the low pressure side space b and is discharged from the permeated refrigerant outlet pipe 107. At this time, R-22 is more easily dissolved, diffused, and released from the functional film 103 than R-13B1, and thus is more easily permeated than R-13B1 and the refrigerant discharged from the permeated refrigerant outlet port 107 is a refrigerant composition of the inlet pipe 105. The ratio of R-22 is higher than that of. On the other hand, the high pressure refrigerant outlet pipe 106 does not pass through the functional film 103.
The more discharged refrigerant composition has a lower R-22 ratio.

Table 1 shows an example of the experimental results.

Although the case where the refrigerant vapor is introduced from the inlet pipe of the separator 101 is shown in the above Table 1, even if the refrigerant liquid or the mixture of the vapor and the liquid is introduced, R-22 is the functional film 103 from R-13B1 similarly. It can be separated because it easily dissolves, diffuses, and separates.

As described above, it has been clarified that the refrigerant can be separated by using the functional film.

In the previous experiment, a benzene solution of dimethyl silicone was spread on water to form an ultra-thin film, and then a polypropylene porous film (Ceraney's: Juraguard)
Although the polymer composite film formed by transfer film formation is used, natural rubber, polyethylene, polyvinyl acetate or the like may be used as the non-porous polymer film material other than dimethyl silicone.

Further, even if a porous polymer membrane, a biological membrane or the like is used and the refrigerant is separated by utilizing the ratio of permeation amounts, it does not depart from the gist of the present invention.

An embodiment of the refrigeration cycle using the functional film will be described below with reference to FIG.

FIG. 3 shows a case where a non-azeotropic mixed refrigerant of R-22 and R-13B1 is used as the refrigerant, and R-13B1 which is difficult to permeate the functional film is stored to make the refrigerant composition ratio of the main circuit variable. An example is shown.

In the figure, 11 is a compressor, 12 is a condenser, 13 is a main expansion device, and 14 is an evaporator, which are sequentially connected in an annular fashion to form a main circuit. On the other hand, the inlet pipe 105 of the separator 101 of the previous configuration is connected to the discharge side of the compressor 11, and the outlet pipe 106 is a reservoir 17,
It is connected to the suction side of the compressor 11 via the sub expansion device 18, and the permeated refrigerant outlet pipe 107 is connected to the suction side of the compressor 11 via the electromagnetic valve 19. Further, the permeated refrigerant outlet pipe 106 is connected to the cooler 20 in a heat exchange manner.

The operation of the refrigeration cycle configured as above will be described below.

First, the case where the refrigerant is not separated will be described.

The refrigerant vapor compressed by the compressor 11 is cooled and liquefied by the condenser 12, reduced in pressure by the main expansion device 13, evaporated in the evaporator 14, and returned to the compressor 11. Here, when the solenoid valve 19 is closed and the sub expansion device 18 is fully closed, the refrigerant discharged from the compressor 11 does not flow into the separator 101 but flows into the condenser 12. Therefore, the refrigerant circulating in the cycle becomes equal to the filling ratio in any part.

Next, a case where the refrigerant is separated will be described.

When the solenoid valve 19 is opened from the above state and the sub expansion device 18 is fully closed, the branched liquid refrigerant flows into the separator 101, and the functional film 1
R-22, which easily passes through 03, is returned to the suction side of the compressor 11 via the solenoid valve 16. On the other hand, it is difficult to pass through the functional film 103
-13B1 is stored in the reservoir 17. Therefore, R of the main circuit
The -13B1 ratio decreases and the R-22 ratio increases.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a structure such as steam, refrigerating machine oil in a refrigeration cycle has a problem of impeding the permeation of a refrigerant by adhering to a functional film of a separation device and significantly reducing the separation performance of the refrigerant. Was there.

In view of the above problems, the present invention is a mixture of a refrigerant mixture and a refrigerating machine oil consisting of a plurality of types of refrigerant, the composition ratio of the refrigerant can be made variable by using a functional film, and also, such as the speedup of refrigerant separation. The purpose is to improve the separation performance.

Means for Solving the Problems In order to solve the above problems, the present invention is a refrigeration cycle in which a mixture of a mixed refrigerant composed of a plurality of types of refrigerant and a refrigerating machine oil is enclosed, and a specific refrigerant among a plurality of types of refrigerants described above. Is connected to a refrigerant separation device having a functional film using an organic film of dimethyl silicone that is easily dissolved, diffused, released, and easily permeated, and an oil separator is provided in the refrigerant inlet pipe of the refrigerant separation device.

Effect According to the present invention, since the oil separator is provided in the refrigerant inlet pipe of the refrigerant separator according to the above configuration, the circulation amount circulating through the oil separator is small, and the oil component in the mixture supplied to the refrigerant separator is small. Can be accurately removed by an oil separator, and the initial permeation state of the refrigerant can be maintained without oil adhering to the functional film.

Example An example of a refrigeration system in which an oil separator is provided in a refrigerant inlet pipe of a separation device using a functional membrane will be described with reference to FIGS. 1 and 2.

First, FIG. 1 shows an embodiment of a refrigerating apparatus.

In the figure, the same parts as those in the conventional example (FIG. 3) are designated by the same reference numerals, and the description thereof will be omitted. An oil separator 21 is provided between the discharge side of the compressor 11 of the main circuit and the separator 101, and the oil separator 2
The inlet pipe 22 of 1 is connected to the main circuit, and the outlet is connected to the inlet pipe 105 of the separator 101. The oil return pipe 23 of the oil separator 21 is connected to the suction side of the compressor 11 in the main circuit via a third expansion device 24.

The operation of the refrigeration cycle configured as described above will be described below.

First, the case where the refrigerant is not separated will be described.

The refrigerant vapor compressed by the compressor 11 is cooled and liquefied by the condenser 12, reduced in pressure by the main expansion device 13, evaporated in the evaporator 14 and returned to the compressor 11. Here, when the solenoid valve 19 is closed and the sub expansion device 18 and the third expansion device 24 are fully closed, the refrigerant discharged from the compressor 11 does not flow into the oil separation 21 and the separator 101,
It flows to the condenser 12. Therefore, the refrigerant circulating in the cycle becomes equal to the filling ratio in any part.

Next, a case where the refrigerant is separated will be described.

When the solenoid valve 19 is opened from the above state, the sub expansion device 18 is fully closed, and the third expansion device 24 is opened a little, the branched refrigerant vapor flows into the oil separator 21.

The refrigerant from which the oil has been removed by the oil separator 21 flows into the separator 101 through the inlet pipe 105 of the separator 101, and R-22, which easily permeates the functional membrane 103, passes through the solenoid valve 19 to the compressor 11 Returned to the suction side. On the other hand, R-13B1 which is less likely to pass through the functional film is cooled and liquefied by the cooler 20 and stored in the reservoir 17. The oil separated by the oil separator 21 is returned to the suction side of the compressor 11 via the third expansion device 24. Therefore, the R-13B1 ratio of the main circuit decreases and the R-22 ratio increases.

Further, FIG. 2 shows the relationship between the amount of permeated refrigerant in the functional membrane and the pressure difference in the space a and the space b when the oil separator 21 is provided and not provided.

It can be seen that the amount of the permeated refrigerant is large compared to the case where the oil separator 21 is provided () and the case where the oil separator 21 is not provided (), and the characteristics are close to the permeated refrigerant amount () of the mixed refrigerant not containing the refrigerating machine oil.

As described above, according to the present embodiment, by removing the oil component in the mixture supplied to the separator 101 by the oil separator 21, it is possible to prevent oil from adhering to the functional film 103 and reduce the amount of permeated refrigerant. Can be prevented. Therefore, the separation performance of the refrigerant can be maintained without reducing the throughput of the mixture.

Effects of the Invention As described below, the present invention separates a mixture of a mixed refrigerant and a refrigerating machine oil consisting of a plurality of kinds of refrigerants, and in a refrigeration cycle in which the composition of the refrigerant is changed, an organic film of dimethyl silicone is used as a functional film. Since it has a good separation performance of a specific refrigerant, and because an oil separator is provided in the refrigerant inlet pipe of the refrigerant separator, the circulation amount circulating through the oil separator is small and the refrigerant is supplied to the refrigerant separator. The oil component in the mixture can be accurately removed by the oil separator, the oil does not adhere to the functional film of the refrigerant separation device, and the decrease in the amount of the refrigerant passing through the functional film can be prevented. Therefore, it is possible to prevent deterioration of the refrigerant separation performance such as the refrigerant processing capacity and the refrigerant concentrating capacity.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram in an embodiment of the present invention, FIG. 2 is a permeation characteristic diagram based on experimental results with and without the use of the oil separator, and FIG. 3 is a refrigeration cycle diagram in a conventional example. FIG. 4 is a detailed sectional view of the refrigerant separator, FIG.
FIG. 6 is a refrigeration cycle diagram using the same rectification separator, and FIG. 6 is a detailed sectional view of the rectification separator. 11 …… Compressor, 12 …… Condenser, 13 …… Main throttling device, 14…
… Evaporator, 21 …… Oil separator, 101 …… Refrigerant separator, 103…
… Functional membrane.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akira Fujitaka 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Akira Nakazawa, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 56) References JP-A-63-238367 (JP, A)

Claims (1)

[Claims] 1. A refrigeration cycle is constituted by enclosing a mixture of a refrigerating machine oil and a mixed refrigerant of a plurality of kinds of refrigerant in a main circuit in which a compressor, a condenser, a main expansion device, and an evaporator are connected in an annular shape. A refrigeration cycle is connected to a refrigerant separation device having a functional film using an organic film of dimethyl silicone, in which a specific refrigerant of the plurality of kinds of refrigerants is easily dissolved, diffused, released, and easily permeated. Refrigerating device with an oil separator installed in the refrigerant inlet pipe.