JPS625051A - Refrigerator using mixed refrigerant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a refrigerator using a mixed refrigerant, and more particularly, a refrigerant mixture of a high boiling point refrigerant and a low boiling point refrigerant is sealed in a refrigerant circuit, and The present invention relates to a refrigerator in which the composition ratio of the refrigerant circulating within the refrigerant circuit can be changed by controlling the storage of a liquid refrigerant rich in high boiling point refrigerant within the refrigerant circuit, thereby adjusting the refrigerating capacity.

(Prior Art) The present applicant has proposed this type of refrigerator in which a mixed refrigerant is sealed in Japanese Patent Application No. 177189/1989.

To roughly explain this based on Fig. 5, the condenser (
50) and evaporation S! i; Liquid pipe (52) connecting to (51)
), the first resistor is set to a resistance value that brings the suction refrigerant into a superheated state.
While installing a capillary reach tube (53), the first
In parallel with the capillary reach tube (53), connect a series circuit of a second capillary reach tube (54), which has a smaller resistance value than the capillary tube (53) and keeps the suction refrigerant in a wet state, and an on-off valve (55). are doing.

Further, an accumulator (58) capable of storing liquid refrigerant and an auxiliary accumulator (59) are interposed in the gas pipe (57) connecting the evaporator (51) and the compressor (58). .

Thus, by closing the on-off valve (55),
Since the suction refrigerant is adjusted to an appropriate superheated state, liquid refrigerant does not remain in the accumulator (58), and therefore, the circulating refrigerant in the refrigerant circuit has the original composition ratio when it was sealed, and exhibits a predetermined refrigerating capacity. On the other hand, when the on-off valve (55) is opened, the suction refrigerant becomes wet, and the liquid refrigerant in this refrigerant is stored in the accumulator (58). Moreover, since the stored refrigerant is a liquid refrigerant rich in high-boiling point refrigerants, the refrigerant circulating in the circuit becomes a mixed refrigerant rich in low-boiling point refrigerants compared to the initial composition ratio, thus increasing the refrigeration capacity. The ability is controlled by the side.

(Problems to be Solved by the Invention) However, in the above conventional system, in order to store liquid refrigerant rich in high boiling point refrigerant in the accumulator (58), the resistance of the capillary tube acting as the expansion mechanism is reduced. Therefore, the suction refrigerant must be actively moistened, and as a result, the evaporator (51)
There was a problem that the evaporation temperature of the evaporation temperature was higher than the optimum evaporation temperature.

Therefore, in the present invention, even when the expansion mechanism provided on the inlet side of the evaporator is set so that the suction refrigerant is in an appropriate superheated state, the refrigerant on the outlet side of the evaporator generally This was invented by focusing on the fact that unevaporated liquid refrigerant rich in high boiling point refrigerant remains, and a container is used to separate and store the unevaporated liquid refrigerant rich in high boiling point refrigerant remaining in the suction refrigerant by gravity. By providing it in the gas pipe leading to the compressor, the capacity can be adjusted by changing the composition ratio of the circulating refrigerant in the refrigerant circuit without having to specifically set the resistance value of the expansion mechanism to control the humidity of the suction refrigerant. The point is to make it possible.

(Means for Solving the Problems) The configuration of the present invention will be explained based on FIG. In a refrigerator in which a side liquid pipe (11) is provided with an expansion mechanism (3) for controlling the degree of superheat, a gas pipe (8) connecting the evaporator (4) and the compressor (1),
A liquid storage container (9) for gravity classifying the liquid refrigerant flowing through the gas pipe (8) is connected via a first passage (10) extending downward from the gas pipe (8), while the liquid storage container In (9), expulsion means for expelling the stored refrigerant is provided.

In FIG. 1, (2) is a condenser, and (5) is an accumulator.

As shown in FIG. 1, the expelling means includes a second passageway (13) that connects the liquid storage container (9) and the high pressure or intermediate pressure region of the refrigerant circuit via an on-off valve (12); A decompression mechanism (14) connects the liquid storage container (9) and the gas pipe (8).
a third passageway (15) connected via the first passageway (
10) from the gas pipe (8) interposed in the liquid storage container (
9) and a check valve (16) that allows flow only to the
Using the pressure in the refrigerant circuit introduced from the second passage (13), the high boiling point refrigerant-rich liquid refrigerant stored in the liquid storage container (9) is pressure-driven from the third passage (15). You can also try to kick them out.

Further, as shown in FIG. 4, the expelling means/means is provided with a heating means (heat exchange tube (8)) using discharged gas in the liquid storage container (9), so that the liquid is heated by the heating means. The liquid refrigerant stored in the storage container (9) may be heated and evaporated to be expelled from the container (9).

(Function) Even if the resistance of the expander (3) is adjusted so that the suction gas refrigerant is in an appropriate superheated state, the gas pipe from the evaporator (4) to the compressor (1) In the refrigerant flowing through (8), unevaporated liquid refrigerant rich in high boiling point refrigerant remains. Therefore, when the expelling means is not activated, the suction refrigerant flows through the gas pipe (8). In the process, the unevaporated liquid refrigerant contained in the refrigerant passes through the first passage (
10) At the connection part, the first passage (1
The refrigerant falls through the refrigerant 0), is separated from the suction refrigerant, and is stored in the liquid storage container (8). As a result,
The composition ratio of the high boiling point refrigerant in the circulating refrigerant decreases, and the refrigerating capacity increases.

On the other hand, when the refrigerant in the liquid storage container (9) is expelled into the circulation circuit of the refrigerant circuit by the expulsion means, the composition ratio of the high boiling point refrigerant in the circulating refrigerant increases, so that the refrigerating capacity decreases.

For example, in the one shown in FIG.
) is opened, high-pressure or intermediate-pressure circulating refrigerant flows into the liquid reservoir (9) through the second passage (13), and this pressure refrigerant causes The high boiling point refrigerant-rich liquid refrigerant stored in (9) is expelled to the gas pipe (8) via the third passage (15).

Moreover, according to the one in FIG. 4, when the liquid storage container (9) is heated by the heating means, the liquid refrigerant rich in high-boiling single point refrigerant stored in the container (9) evaporates, and It is expelled from one passage (10) to the gas pipe (8).

(First embodiment) What is shown in Fig. 1 is a compressor (1), a condenser (2), an electric expansion valve for superheat control (3), an evaporator (4), and an accumulator (5). are connected in sequence to form a refrigerant circuit.

A mixed refrigerant made by mixing R22, which is a low boiling point refrigerant, and R114, which is a high boiling point refrigerant, at a ratio of 3:1 is sealed in this refrigerant circuit.

Further, the expansion valve (3) is adjusted to control the refrigerant sucked into the compressor (1) to an appropriate degree of superheat.

Note that (6) is a liquid receiver, and (7) is an auxiliary accumulator.

In the refrigerator configured as described above, the evaporator (4
) and the compressor (1), a liquid storage container (9) is provided on the inflow side of the accumulator (5) in the gas pipe (8) that connects the compressor (1).
It connects. Specifically, in the gas pipe (8),
A first passage (10) extending downward is connected to the gas pipe (8), and the liquid reservoir (9) consisting of a hollow vessel is connected to the lower outlet side of the passage (10).

Thus, the liquid refrigerant in the suction refrigerant flowing through the gas pipe (8) falls from the first passage (10) connection part to the liquid storage container (9) through the passage (10) due to its gravity. The liquid is stored in the liquid storage container (9).

Further, the high pressure region of the refrigerant circuit, for example, the condenser (2
) and the evaporator (4), the inlet side portion of the expansion valve (3) and the liquid reservoir container (9
) between the aqueous emulator (5) and the auxiliary accumulator (7) in the gas pipe (8), and
The liquid storage container (9) is connected to the capillary tube (14).
) is connected by a third passageway (15) intervening therein, and furthermore, the gas pipe (8) is connected to the first passageway (!0) through the liquid storage container (!0).
A check valve (16) is installed to allow flow only to 9).

Thus, these second passages (13) and third passages (14)
and the check valve (16) forms a discharging means for discharging the liquid refrigerant stored in the liquid storage container (9) from the container (9) into the circulation circuit, and the second passage ( By opening the on-off valve (12) installed in the liquid refrigerant (13), high-pressure liquid refrigerant flows from the liquid pipe (11) into the liquid storage container (9) and is stored in the liquid storage container (9). The liquid refrigerant that has been stored is sequentially expelled through the third passageway (14), so that the refrigerant in the liquid storage container (9) can be replaced with this high-pressure liquid refrigerant.

Note that another pressure reducing mechanism may be installed in the third passage (15) instead of the capillary tube (14).

The operation of the refrigerator configured as above will be explained below.

When the capacity of the refrigerator is increased, the on-off valve (12) interposed in the second passage (13) is closed.

Although the suction refrigerant is controlled to an appropriate degree of superheating by the expansion valve (3), the refrigerant flowing out from the evaporator (4) contains liquid refrigerant rich in high boiling point refrigerant, which causes evaporation delay. It remains as an unevaporated liquid refrigerant. When the suction refrigerant containing this unevaporated liquid refrigerant flows through the gas pipe (8) and reaches the connection part of the first passage (10), at the connection part, the unevaporated liquid refrigerant is transferred to the first passage by gravity. 1 aisle (1
0) into the liquid storage container (9). In this way, a liquid refrigerant rich in high boiling point refrigerant is stored in the liquid storage container (9).

Therefore, the composition ratio of the high boiling point refrigerant in the refrigerant circulating in the refrigerant circuit decreases, in other words, the composition ratio of the low boiling point refrigerant in the circulating refrigerant increases, so that the refrigeration capacity increases.

Incidentally, the temperature of the liquid storage container (-9) is maintained at about 20° C. to 30° C. to prevent evaporation of the high boiling point refrigerant.

On the other hand, when the capacity of the refrigerator is lowered from the above-mentioned state, the on-off valve (
12).

In this way, the high-pressure liquid refrigerant flowing through the liquid pipe (11),
That is, the circulating refrigerant of the refrigerant circuit flows into the liquid storage container (9) via the second passage (13). Therefore, the liquid refrigerant stored in the container (9) is mixed with the high-pressure liquid refrigerant, and together with this high-pressure liquid refrigerant, the pressure is reduced through the third passage (14) and the gas pipe (8 ). Then, eventually, liquid refrigerant having the same composition ratio as the circulating refrigerant of the refrigerant circuit will remain in the liquid storage container (9).

Therefore, the composition ratio of the circulating refrigerant returns to the original composition ratio of the mixed refrigerant sealed in the refrigerant circuit. In other words, the composition ratio of the high boiling point refrigerant in the circulating refrigerant becomes higher than the above state, and the refrigerating capacity increases. It declines.

In addition, since the check valve (16) is interposed in the first passage (10), the liquid reservoir container (
The liquid refrigerant does not flow back from 9) to the gas pipe (8).

Further, in the above embodiment, the connection point of the third passageway (15) to the liquid storage container (9) may be at an upper position of the container (9).

Further, the inflow side of the second passage (13) may be connected to a high pressure gas region in the refrigerant circuit, that is, a discharge gas pipe (17) on the outlet side of the compressor (1).

Further, as a discharging means for pressurizing the liquid refrigerant stored in the liquid storage container (9), the liquid refrigerant stored in the container (9) can be removed from the liquid refrigerant stored in the container (9) without providing the third passage (15). One passage (10) may be used to allow the gas to flow out into the gas pipe (8). In this case, the check valve (IB) is not provided in the first passageway (10), or a capillary tube is connected in parallel to the check valve (16).

(Second Embodiment) The embodiment shown in FIG. 2 has the following features in addition to the embodiment shown in FIG.
A heating means is provided to adjust the temperature of the liquid storage container (9).

The reason why the heating means is provided in this way is that the liquid storage container (9
) may be maintained at a temperature below the evaporation temperature of the liquid refrigerant stored in the container (9), for example, 20 to 30°C as described above. By keeping the temperature slightly lower than the saturation temperature corresponding to the evaporation pressure of the high-boiling point refrigerant, a higher purity refrigerant of the high-boiling point refrigerant can be stored in the container (9), so that the composition ratio of the circulating refrigerant can be made lower than that of the low-boiling point refrigerant. It can be changed to the rich side, and the range of ability changes can be further expanded.

The heating means will be specifically explained below.

That is, the heat exchange tube (18) is wrapped around the liquid storage container (9), and the compressor (
Connecting a bypass pipe (19) that branches from the discharge gas pipe (17) of 1) and bypasses a part of the discharge gas, and
This bypass pipe (19) is provided with an electromagnetic on-off valve (20).

Thus, by controlling the opening and closing of the on-off valve (20), the temperature of the liquid reservoir (9) can be maintained at a temperature slightly lower than, for example, the saturation temperature corresponding to the evaporation pressure of the high-boiling refrigerant.

Further, as a heating means for adjusting the temperature of the liquid storage container (9), an electric heater may be attached to the liquid storage container (9) instead of the heat exchange tube (18).

(Third Embodiment) What is shown in FIG. 3 is an application of the embodiment shown in FIG. 1 to a heat pump type refrigerator.

The difference from the one in Fig. 1 is that the first passage (10) is connected to the gas pipe (8-a) that connects the four-way switching valve (2J) and the compressor (1). be. Furthermore, (3a)
(3b) are first and second electric expansion valves, and during cooling operation, the first electric expansion valve (3a) is operated to control the degree of superheating of the intake gas; )
I'm trying to close it completely. Also, during heating operation,
The first and second electric expansion valves (3a) and (3b) are operated in the opposite direction to that during cooling operation.

Further, the first and second electric expansion valves (3a) (3b)
is controlled simultaneously during cooling and heating operations, that is, during cooling operation, the degree of superheat of the suction gas refrigerant is controlled by the first electric expansion valve (3a), while the second electric expansion valve (3a) is controlled simultaneously during the cooling and heating operations.
3b) may be used to control the degree of supercooling of the high-pressure liquid refrigerant.

In this case, the intermediate pressure refrigerant between the expansion valves (3a) and (3b) may be introduced into the liquid storage container (9) via the second passage (13).

(Fourth Embodiment) The embodiment shown in FIG. 4 differs from the embodiment shown in FIG. 1 in the expulsion means for expelling the high-boiling liquid refrigerant stored in the liquid storage container (9). .

That is, in the one shown in FIG. 4, only a heating means for heating the liquid storage container (9) is provided in the liquid storage container (9). Specifically, a heat exchange tube (18) is wrapped around the liquid storage container (9), and a heat exchange tube (18) is wrapped around the discharge gas pipe (17).
Bypass pipe (19) that bypasses a part of the discharged gas from
), the bypass pipe (19) is connected to the heat exchange tube (18), and the bypass pipe (19) is connected to the heat exchange tube (18).
) is equipped with an on-off valve (20).

Thus, when discharging the liquid refrigerant rich in high boiling point refrigerant stored in the liquid storage container (9), the on-off valve (20
), the discharge gas is made to flow through the heat exchange tube (18), and the temperature of the container (9) is maintained at a temperature higher than the saturation temperature corresponding to the evaporation pressure of the high boiling point refrigerant. Then, the high boiling point refrigerant-rich liquid refrigerant stored in the liquid storage container (9) evaporates and is expelled from the first passageway (10) to the gas pipe (8).

In the above embodiment, an electric expansion valve (3) is used as an expansion mechanism installed in the liquid pipe (11), but other expansion means may be used.

(Effects of the Invention) As described above, according to the present invention, the resistance value of the expansion mechanism is set to an appropriate value that brings the suction refrigerant into a superheated state without setting it particularly small so as to make the suction refrigerant wet. Since the composition ratio of the circulating refrigerant can be changed to the low-boiling refrigerant-rich side by storing a liquid refrigerant rich in high-boiling refrigerant in the liquid storage container, the evaporation in the evaporator can be adjusted to increase the refrigerating capacity. This allows the temperature to be set at an optimal temperature, such as being able to set it to a lower temperature than in the past.

[Brief explanation of the drawing]

1 to 4 are detailed explanatory diagrams of the present invention. FIG. 1 is a refrigerant circuit diagram of the first embodiment, FIG. 2 is a partial diagram of the refrigerant circuit of the second embodiment, and FIG. 3 is a diagram of the refrigerant circuit of the second embodiment. FIG. 4 is a refrigerant circuit diagram of the fourth embodiment, and FIG. 5 is a refrigerant circuit diagram of a conventional example. (1)...Compressor (3)...Expansion mechanism (4)...Evaporator (8)...Gas pipe (9)...Liquid reservoir Container (10)...First passage (11)...Liquid pipe (12)...On-off valve (13)...Second passage (14)...・Capillary tube (15)・・
...Third passage (16)...Check valve

Claims (3)

[Claims] (1) In a refrigerator in which a mixed refrigerant is sealed and an expansion mechanism (3) for superheat control is provided in the liquid pipe (11) on the inlet side of the evaporator (4), the evaporator (4) and the compressor (1)
This gas pipe (8) is connected to the gas pipe (8) through a first passage (10) extending downward from the gas pipe (8).
Refrigeration using a mixed refrigerant, characterized in that a liquid refrigerant is connected to the liquid refrigerant (9) for gravity separation of the liquid refrigerant flowing through the liquid refrigerant, and a discharging means is provided for expelling the liquid refrigerant stored in the liquid refrigerant (9). Machine. (2) The expelling means connects a second passageway (13) connecting the liquid storage container (9) and the high pressure or intermediate pressure region of the refrigerant circuit via an on-off valve (12), and the liquid storage container ( 9) and the gas pipe (8) via a pressure reducing mechanism (14), and a third passage (15) that connects the gas pipe (8) to the gas pipe (8) interposed in the first passage (10). A refrigerator using a mixed refrigerant according to claim 1, comprising a check valve (16) that allows flow only into the container (9). (3) A refrigerator using a mixed refrigerant according to claim 1, wherein the expelling means comprises a heating means for heating the liquid storage container (9).