JPH0781751B2 - 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. 3 and 4.

FIG. 3 is a refrigeration cycle diagram showing a conventional example, and FIG. 4 is a sectional view of a rectification column for changing the composition ratio of the non-azeotropic mixed refrigerant.

In FIG. 3, 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 population of the rectification tower 6 are connected by a pipe 10, and the heater 5 is connected to the pipe 10 by heat exchange. The lower outlet of the rectification tower 6 and the population of the evaporator 4 in the main circuit are connected to each other via pipes 11 and 12 via an auxiliary expansion device 7. In addition, a condenser 8 is provided above the rectification tower 6.
And a reservoir 9 are provided, and the reservoir 9 is connected to the rectification column 6 in an annular shape by pipes 13 and 14. Further, the cooler 8 and the pipe 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. 4, 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 tower 6, enters the reservoir 9 through the pipe 13, and returns to the rectification tower 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 component inside the reservoir 9 does not rise, 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, and is liquefied into the reservoir 9.
The drop A between the reservoir 9 and the return pipe 14 of the rectification tower 6 is set in advance.
A part of the liquid refrigerant from the reservoir 9 is returned to the rectification tower 6 through the pipe 14 again by the drop A, and the packing material 602 is provided.
The rectifying column stores a refrigerant having a large amount of low-boiling point components in the reservoir 9 by making a rectifying action by heat exchange and mass transfer by making a vapor-liquid contact with the vapor that rises halfway through the gap. From the lower part of 6, the refrigerant with a low low boiling point component is pipe 11,
It flows into the main circuit through the auxiliary 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.

Problems to be Solved by the Invention However, the above-described 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 column and the reservoir, a certain head A shown in FIG. 4 is set so that the liquid stored in the reservoir returns to the rectification column 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 gas component generated in the heater rises in the rectification tower and enters the reservoir, but at this time, it must be cooled by the refrigerant sucked into the compressor in order to liquefy this gas component, resulting in loss of refrigeration capacity. Cause

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 view of the above problems, it is an object of the present invention to eliminate restrictions on attachment and installation of components of a separation circuit, reduce the size and simplification of the separation circuit, and realize a separation circuit without heat loss.

Means for Solving the Problems In order to solve the above problems, the present invention relates to a refrigeration cycle in which a plurality of types of refrigerants are sealed, and a permeation rate of a specific refrigerant among a plurality of types of refrigerants is permeation of another refrigerant. With a functional film higher than the ratio, it has an inlet pipe connected between the condenser and the main expansion device, and has a permeated refrigerant outlet pipe connected between the evaporator and the compressor via a solenoid valve. A refrigerant separator having an outlet pipe connected between the main expansion device and the evaporator via the expansion device is provided, and the separator has a space volume for storing the non-permeable refrigerant or the permeated refrigerant. .

Effect The present invention, by the above configuration, can separate the refrigerant not only for the non-azeotropic mixed refrigerant but also for the azeotropic mixed refrigerant, eliminating the restrictions on the mounting and installation of the components of the separation circuit, downsizing and simplification of the separation circuit, and heat. It is possible to realize a separation circuit without loss.

Example First, an experimental result that clarifies that a functional film can be used for refrigerant separation will be described.

FIG. 1 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 divided into a non-permeate side space a and a permeate 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. Also, the separator body 102,
High-pressure refrigerant inlet pipe 105, outlet pipe 106, permeated refrigerant outlet pipe
107 is provided.

In the separator with the above structure, a benzene solution of dimethyl silicone was spread on water as a functional film to make it an ultra-thin film, and then a thin film formed by transfer film formation on a porous polypropylene film (Ceraney's: Jura Guard) 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 non-permeate side space a in the separator body 102. Here, due to the pressure difference between the non-permeate side space a and the permeate side space b, a part of the refrigerant permeates into the permeate side space b and is discharged from the permeate refrigerant outlet pipe 107. At this time, R-22 is more likely to permeate than R-13B1, and the ratio of R-22 in the refrigerant discharged from the permeated refrigerant outlet pipe 107 is higher than that in the inlet pipe 105. On the other hand, the high pressure refrigerant outlet pipe 106 without passing 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.

In Table 1 above, the case where the refrigerant vapor is introduced from the artificial pipe of the separator 101 is shown, but the refrigerant liquid or the mixture of the vapor and the liquid can be introduced to separate the refrigerant vapor.

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. 2 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 a ring to form a main circuit. On the other hand, the inlet pipe 105 of the separator 101 having the above configuration is connected to the high pressure side before the main expansion device 13, and the outlet pipe 106
Is connected to the low pressure side after the main expansion device 13 via the sub expansion device 17, and the permeated refrigerant outlet pipe 107 is connected to the suction side of the compressor via the solenoid valve 16. Here, the separator 101 has a large non-permeation side space a and also has a function of storing the non-permeation refrigerant.

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 16 is closed and the sub expansion device 17 is opened, the liquid refrigerant branched from the front of the main expansion device 13 flows into the separator 101, does not pass through the functional film 103, and is directly sub-flowed from the outlet pipe 106. Evaporator 14 via throttling device 17
Returned to the entrance. Therefore, the refrigerant circulating in the cycle becomes equal to the filling ratio in every part.

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

When the solenoid valve 16 is opened from the above state and the sub expansion device 17 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 inlet of the evaporator 14 via the solenoid valve 16. On the other hand, R-1 which is difficult to pass through the functional film 103
3B1 is stored in the high pressure side space a of the separator 101. Therefore, the R-13B1 ratio of the main circuit decreases and the R-22 ratio increases.

As described above, according to the present embodiment, the refrigerant composition of the main circuit can be changed according to the purpose of high efficiency, high capacity, etc. without the need for a heater or the like. Further, since there is no restriction on the mounting of the components of the separation circuit, the separation circuit can be downsized and simplified. Further, by connecting the inlet of the separator to the outlet of the condenser, the refrigerant enters in the liquid phase having a large specific volume, so that cooling for liquefaction is not necessary and the space for storing is small.

Furthermore, since the separator 101 also has a refrigerant storage function in the non-permeate side space a, it is not necessary to provide a separate reservoir, and the components of the refrigerant separation circuit can be simplified.

In the present embodiment, the separator 101 has the refrigerant storage function in the non-permeation side space a, but it is clear that the same effect can be obtained even if the separator 101 also has the refrigerant storage function.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to change the composition of a plurality of types of refrigerant in the main circuit without the need for a heater or the like, and there is no restriction on mounting and installing the components of the separation circuit. Therefore, there is an effect that the separation circuit can be downsized and simplified. Further, since the refrigerant at the inlet of the separator is in the liquid phase, it is not necessary to cool the refrigerant to be stored, and therefore the refrigerating capacity is not lost. Further, since the liquid refrigerant has a large specific volume, it has an effect that the volume to be stored can be small. Furthermore, since the separator has a space volume for storing the non-permeable refrigerant or the permeated refrigerant, it is not necessary to separately provide a reservoir, and the components of the refrigerant separation circuit can be simplified.

[Brief description of drawings]

FIG. 1 is a detailed sectional view of a separator constituting a refrigerating apparatus according to an embodiment of the present invention, FIG. 2 is a refrigeration cycle diagram showing a different embodiment when the same separator is used, and FIG. FIG. 4 is a detailed sectional view of the rectification column in the refrigeration cycle in the example. 11 …… Compressor, 12 …… Condenser, 13 …… Main throttling device, 14…
… Evaporator, 101 …… Separator, 103 …… Functional membrane.

Front page continuation (72) Inventor Koji Murozono 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinji Watanabe 1006, Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Person Takaaki Fujitaka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References Japanese Patent Laid-Open No. 63-238367 (JP, A)

Claims (1)

[Claims] 1. A refrigeration cycle in which a plurality of types of refrigerants are enclosed in a main circuit in which a compressor, a condenser, a main expansion device, and an evaporator are sequentially connected in an annular shape, and a specific refrigerant permeates among the plurality of types of refrigerants. With a functional film whose ratio is higher than the permeation ratio of other refrigerants, it has an inlet pipe connected between the condenser and the main expansion device, and was connected between the evaporator and the compressor via a solenoid valve. A refrigerant separator having a permeating refrigerant outlet pipe and having an outlet pipe connected between the main throttling device and the evaporator via a subthrottle device is provided, and the separator stores the non-permeating refrigerant or the permeating refrigerant. A refrigeration system having a space volume.