JPH071127B2 - Refrigerator control device - 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, in particular, as a method for varying the composition of the refrigerant circulating in the cycle of the refrigeration system using a non-azeotropic mixed refrigerant, separation using a functional film that facilitates the permeation of a specific refrigerant among a plurality of types of refrigerants. The division formula is used (for example, JP-A-63
-243662 publication).

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

FIG. 5 is a sectional view of a refrigerant separator (hereinafter simply referred to as a separator) using a functional film for changing the composition ratio of the non-azeotropic mixed refrigerant, and FIG. 6 is a refrigeration cycle diagram showing a conventional example.

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

In FIG. 5, 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. 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 (Ceraneys Co., Ltd .: Jura Guard) was prepared. A case where the mixed refrigerant of R-22 and R-13B1 is used as a molecular composite membrane and is separated 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 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.

Although Table 1 shows the case where cold heat vapor is introduced from the inlet pipe of the separator 101, it can be separated even if a refrigerant liquid or a mixture of vapor and liquid is introduced.

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

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

FIG. 6 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, 1 is a compressor, 2 is a condenser, 3 is a main expansion device, and 4 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 having the above structure is connected to the high pressure side before the main expansion device 3, the outlet pipe 106 is connected via the auxiliary expansion device 7, and the permeated refrigerant outlet pipe 107 is connected to the two-way valve 6. It is connected via the main expansion device 3 to the low-voltage side. Here, the separator 101 has a large high pressure side space a,
It also has the function of storing the 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 1 is cooled and liquefied by the condenser 2, reduced in pressure by the main expansion device 3, evaporated in the evaporator 4, and returned to the compressor 1. Here, when the solenoid valve 6 is closed and the sub expansion device 7 is opened, the liquid refrigerant branched from the front of the main expansion device 3 flows into the separator 101, does not pass through the functional film 103, and is directly sub outlet from the outlet pipe 106. Evaporator 4 via expansion device 7
Returned to the entrance. 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 6 is opened from the above state and the sub expansion device 7 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 4 via the solenoid valve 6. 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, the composition ratio of the main circuit refrigerant can be made variable by controlling the valve opening degree of the sub expansion device 7.

SUMMARY OF THE INVENTION However, the above-mentioned configuration has a problem that the functional film is damaged when the pressure difference between the inlet of the separator and the outlet of the permeated refrigerant becomes larger than a certain value.

The present invention has been made in view of the above problems and aims at protecting a functional film.

Means for Solving the Problems In order to solve the above problems, the present invention provides a control device for controlling the throttle amount of a sub-throttle device, which detects an electric pressure difference between an inlet and a permeate side outlet of a refrigerant separator. Differential pressure detecting means for converting, comparing means for comparing the electric signal output from the differential pressure detecting means and the set electric signal, and outputting a control signal,
A storage unit that stores an output mode for controlling the opening and closing of the sub diaphragm device, a selection unit that selects one of the output modes of the storage unit according to the control signal output from the comparison unit, and an output of the storage unit. The output means is configured to control the opening / closing of the sub diaphragm device according to the mode.

Action The present invention can protect the functional film with the above configuration.

Embodiment A control device for a refrigerating apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a refrigeration cycle diagram in the embodiment of the present invention.

In the figure, 11 is a compressor, 12 is a condenser, 13 is a main expansion device, and 14 is an evaporator, which are annularly connected to form a main circuit.
On the other hand, the inlet of the refrigerant separation device 101 incorporating the functional film 103 is connected to the outlet of the condenser 12 through the auxiliary expansion device 15, the outlet of the refrigerant separation device 101 is provided through the two-way valve 16, and the refrigerant separation device 1
The permeated refrigerant side outlet of 01 is connected between the inlets of the evaporator 14 via a two-way valve 17.

Next, in FIG. 2, the control circuit includes a microcomputer (hereinafter referred to as LSI) 18 for controlling the entire refrigeration system, a differential pressure for detecting a differential pressure between the inlet and the permeate side outlet of the refrigerant separation device 101, and converting the differential pressure into an electric signal. Sensor 19, resistance circuits 20 and 21 that output a set differential pressure, step motor 22 and step motor drive device 23 that control the opening of sub-throttle device 15, coils 24 and 25 that open and close two-way valves 16 and 17, LSI 18 It is composed of an amplifier 26 for amplifying the output signal of and a relay 27, 28 for energizing the coils 24, 25.

The control circuit shown in FIG. 2 and the block diagram shown in FIG. 3 will now be described. The resistance circuits 20 and 21 for outputting the set differential pressure shown in FIG. 2 correspond to the set electric signal shown in FIG. The differential pressure sensor 19 shown in FIG. 2 corresponds to the differential pressure detecting means shown in FIG. The LSI 18 shown in FIG. 2 controls the opening / closing of the sub-throttle device 15 and the comparing means for comparing and judging the electric signal output from the differential pressure detecting means shown in FIG. It corresponds to a storage unit that stores the output mode and a selection unit that selects one of the output modes of the storage unit according to the control signal output from the comparison unit. Then, the step motor 22 and the step motor drive device 23 for controlling the opening degree of the sub-throttle device 15 of FIG. 2 and the coil 2 for opening and closing the two-way valves 16 and 17 are shown.
4, 25, the amplifier 26 for amplifying the output signal of the LSI 18, and the relays 27, 28 for energizing the coils 24, 25 correspond to the output means in FIG.

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 two-way valve 17 is closed and the two-way valve 16 is opened, the liquid refrigerant branched from the front side of the main expansion device 13 is decompressed by the sub expansion device 15, flows into the separator 101, and permeates the functional film 103. Without being returned, it is directly returned to the inlet of the evaporator 14. 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 two-way valve 16 is opened and the two-way valve 17 is opened from the above state, the branched refrigerant is decompressed by the sub expansion device 15, flows into the separator 101, and R-22 which easily permeates the functional film 103 is It is returned to the inlet of the evaporator 14 via the one-way valve 17. On the other hand, R-13B1 which hardly permeates the functional film 103 is stored in the high pressure side space a of the separator 101. Therefore, the R-13B1 ratio of the main circuit decreases, and
-22 Ratio increases.

At this time, the pressure difference Δ between the inlet of the separator 101 and the outlet of the permeated refrigerant side Δ
When P becomes larger than the first set value ΔP1, the functional film 10
3 is damaged. Therefore, the output signal ΔP of the differential pressure sensor 19
And the set electric signal ΔP1 are compared by the comparison means built in the LSI 18, and when ΔP> ΔP1, the first output mode of the storage means is selected by the selection means and the valve opening degree of the sub-throttle device 15 is reduced. As a result, a control signal is output to the step motor drive device 23 to reduce ΔP.

When ΔP becomes smaller than the second set value ΔP2, the second output mode of the storage means is selected by the selection means and the control signal is sent from the LSI 18 to the step motor drive device 23 so as to increase the valve opening degree of the auxiliary throttle device 15. It is output and increases ΔP.

As described above, the functional film 103 can be protected by detecting the pressure difference ΔP between the inlet of the separator 101 and the permeated refrigerant side outlet and controlling the pressure difference ΔP.

EFFECTS OF THE INVENTION As described above, the present invention has an effect that the functional film can be protected by detecting the pressure difference ΔP between the inlet of the separator and the permeated refrigerant side outlet and controlling the pressure difference ΔP. .

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram in an embodiment of the present invention, FIG. 2 is a control circuit diagram embodying a control device of a refrigeration system of the present invention, and FIG. 3 is a block diagram showing the control device by a function realizing means. FIGS. 4 and 5 are flowcharts of the control device, FIG. 5 is a detailed sectional view of a separator in a conventional example, and FIG. 6 is a refrigeration cycle diagram in the conventional example. 11 …… Compressor, 12 …… Condenser, 13 …… Main throttling device, 14…
… Evaporator, 15 …… Sub throttle device, 16,17 …… Two-way valve, 19…
… Differential pressure sensor, 101 …… Refrigerant separation device, 103 …… Functional membrane.

Front Page Continuation (72) Inventor Shinji Watanabe 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-63-238367 (JP, A)

Claims (1)

[Claims] 1. A refrigeration cycle in which a plurality of types of refrigerant are enclosed in a main circuit in which a compressor, a condenser, a main expansion device, and an evaporator are connected in an annular shape, and a specific refrigerant of the plurality of types of refrigerant is permeated. The inlet of the refrigerant separation device having a functional film to facilitate is connected via the condenser outlet and the sub-throttle device, the outlet of the refrigerant separation device, and the permeated refrigerant side outlet of the refrigerant separation device via a two-way valve. A refrigerating device connected between the inlets of the evaporator and a control device for controlling the throttle amount of the sub-throttle device to detect the differential pressure between the inlet and the permeate side outlet of the refrigerant separator. Differential pressure detecting means for converting into an electric signal, comparing means for comparing and judging the electric signal output from the differential pressure detecting means with a set electric signal, and outputting a control signal, and an output for controlling opening / closing of the sub-throttle device A storage means that stores the mode A refrigeration apparatus comprising a selection means for selecting one of the output modes of the storage means by a control signal output from the comparison means, and an output means for controlling the opening / closing of the sub-throttle device according to the output mode of the storage means. Control device.