JP2003106693A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent liquid return into a suction port on intermediate pressure side of a two-stage compression compressor and dew condensation in a suction pipe for a refrigerating chamber, when an excessive load is applied to a freezing chamber. SOLUTION: A refrigerator according to this invention is provided with a refrigerating cycle 37 constituted by the two-stage compression compressor 2 having a suction port 2c on low pressure side and the suction port 2b on intermediate pressure side, a condenser 3, an evaporator 5 for the refrigerating chamber, and an evaporator 9 for the freezing chamber to exchange heat of refrigerant coming out of the evaporator 5 for the refrigerating chamber and refrigerant coming out of the evaporator 9 for the freezing chamber. According to this configuration, refrigerant density at the suction port 2c on low pressure side of the two step compressor 2 is increased, refrigerant flow rate of the evaporator 9 for the freezing chamber is increased, and liquid return into the suction port 2b on intermediate pressure side and dew condensation in the suction pipe 7 for the refrigerating chamber is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having a refrigerating cycle including a two-stage compression compressor, a condenser, a refrigerator compartment evaporator, and a freezer compartment evaporator.

[0002]

2. Description of the Related Art An example of a refrigeration cycle incorporated in a refrigerator of this type is shown in FIG. In the refrigeration cycle 1, as shown in FIG. 4, the high-pressure gas refrigerant discharged from the high-pressure side discharge port 2a of the two-stage compression compressor 2 is condensed in the condenser 3 to become a two-phase refrigerant. This high-pressure two-phase refrigerant is decompressed by the first expansion device 4 to become an intermediate-pressure two-phase refrigerant, and this two-phase refrigerant enters the refrigerator compartment evaporator 5.

In the evaporator 5 for the refrigerating compartment, a part of the refrigerant evaporates, enters the gas-liquid separator 6 in a two-phase state, and is separated into a liquid refrigerant and a gas refrigerant. The gas refrigerant separated in the gas-liquid separator 6 enters the intermediate pressure side suction port 2b of the two-stage compression compressor 2 through the R suction pipe (refrigerating chamber side suction pipe) 7. The liquid refrigerant separated in the gas-liquid separator 6 is decompressed by the second expansion device 8 to become a low-pressure two-phase refrigerant, and this two-phase refrigerant enters the freezer compartment evaporator 9. The refrigerant evaporated in the freezer compartment evaporator 9 passes through the F suction pipe (freezer compartment side suction pipe) 10 and enters the low pressure side suction port 2c of the two-stage compression compressor 2.

In the two-stage compression compressor 2, the low pressure refrigerant sucked from the low pressure side suction port 2c is
It is pressurized to an intermediate pressure in the first stage compression chamber (not shown).
The intermediate pressure refrigerant pressurized to the intermediate pressure joins and is mixed with the intermediate pressure refrigerant sucked from the intermediate pressure side suction port 2b. The combined and mixed refrigerant is pressurized to a high pressure in a second-stage compression chamber (not shown) and then discharged from the high-pressure side discharge port 2a.

Next, another example of the refrigerating cycle having the two-stage compression compressor 2 is shown in FIG. In this refrigeration cycle 11, as shown in FIG. 5, the high-pressure gas refrigerant discharged from the high-pressure side discharge port 2a of the two-stage compression compressor 2 is condensed in the condenser 3 to become a two-phase refrigerant. This high-pressure two-phase refrigerant is divided into two by the flow divider 12 to obtain the first
The second diaphragm device 4 and the second diaphragm device 8 are entered.

The high-pressure two-phase refrigerant that has entered the first expansion device 4 is decompressed here to become an intermediate-pressure two-phase refrigerant and enters the refrigerator compartment evaporator 5. In the refrigerator compartment evaporator 5, the refrigerant evaporates and enters the intermediate pressure side suction port 2b of the two-stage compression compressor 2 through the R suction pipe 7. Further, the high-pressure two-phase refrigerant that has entered the second expansion device 8 is decompressed here to become a low-pressure two-phase refrigerant and enters the freezer compartment evaporator 9. In the evaporator 9 for the freezer compartment, the refrigerant evaporates, passes through the F suction pipe 10 and the low pressure side suction port 2c of the two-stage compression compressor 2.
to go into. The pressurizing operation of the refrigerant in the two-stage compression compressor 2 is the same as that of the two-stage compression compressor 2 of the refrigeration cycle 1 described above.

The refrigeration cycle 1 or 1 having such a configuration
In the case of 1, the set temperatures of the refrigerator compartment evaporator 5 and the freezer compartment evaporator 9 can be set considerably freely, and the evaporators 5 and 9 can be continuously cooled. For this reason,
Since the efficiency of the refrigeration cycles 1 and 11 can be improved and the set temperature of the refrigerator compartment evaporator 5 can be set high, the amount of frost formed on the refrigerator compartment evaporator 5 can be reduced to achieve refrigeration. The humidity in the room can be kept high. Incidentally, as a publication showing a technique related to such a refrigeration cycle, there is JP-A-11-223397.

[0008]

However, in the refrigerating cycles 1 and 11 having the above-mentioned structure, when an excessive load is applied to the freezing compartment, it becomes difficult for the refrigerant to flow in the evaporator 9 for the freezing compartment, and the refrigerating compartment becomes effective. In some cases, the cooling cannot be performed effectively, that is, the freezing capacity is insufficient. In order to compensate for this lack of refrigerating capacity, it is conceivable to take measures to increase the rotation speed of the two-stage compression compressor 2. However, if controlled in this way, the refrigerating chamber will be over-cooled, or the refrigerating chamber evaporator 5 will not be able to completely evaporate the refrigerant, and the liquid return to the intermediate pressure side suction port 2b of the two-stage compression compressor 2 and the R suction pipe 7 will occur. Could cause dew condensation.

If the above control is performed in the refrigeration cycle 1, the proportion of the liquid refrigerant in the refrigerant discharged from the refrigerating compartment evaporator 5 increases, and the gas-liquid separator 6 cannot complete the phase separation. The two-phase refrigerant flows through the R suction pipe 7. Therefore, the same problem as in the case of the refrigeration cycle 11 occurs.

Therefore, an object of the present invention is to provide a refrigeration cycle using a two-stage compression compressor, and when an excessive load is applied to the refrigeration chamber, the intermediate pressure side suction port of the two-stage compression compressor is introduced. Another object of the present invention is to provide a refrigerator capable of preventing liquid return and dew condensation on the suction pipe for the refrigerator compartment.

[0011]

A refrigerator of the present invention comprises a two-stage compression compressor having a low-pressure side suction port and an intermediate-pressure side suction port, a condenser, a refrigerator compartment evaporator, and a freezer compartment evaporator. The refrigerating cycle constituted by the above is characterized in that the refrigerant discharged from the refrigerating compartment evaporator and the refrigerant discharged from the freezing compartment evaporator are heat-exchanged.

In the above structure, when an excessive load is applied to the freezing compartment, the refrigerating compartment evaporator may not be able to completely evaporate the refrigerant by performing control to increase the rotation speed of the two-stage compression compressor. Even if it does, since the refrigerant discharged from the refrigerator evaporator and the refrigerant discharged from the freezer evaporator are heat-exchanged, it is possible to increase the refrigerant density at the low pressure side suction port of the two-stage compression compressor. As a result, the refrigerant flow rate of the freezer compartment evaporator can be increased, and the cooling capacity of the freezer compartment can be increased. Then, it is possible to prevent the liquid from returning to the suction port on the intermediate pressure side and the dew condensation on the suction pipe for the refrigerating compartment.

Further, in the case of the above construction, in the refrigeration cycle, the discharge port of the two-stage compression compressor is connected to the condenser, and the outlet of the condenser is connected to the first expansion device,
An outlet of the first expansion device is connected to the refrigerating compartment evaporator, an outlet of the refrigerating compartment evaporator is connected to a first flow divider, and one outlet of the first diverter is connected to the refrigerating compartment. It is connected to the intermediate pressure side suction port of the two-stage compression compressor via the side suction pipe, the other outlet of the first flow divider is connected to the second expansion device, and the outlet of the second expansion device is connected to the refrigeration system. And a refrigerating compartment side suction pipe connected to a low temperature side suction pipe of the two-stage compression compressor via a freezing compartment side suction pipe. It is preferable that the suction pipe on the freezer side is exchanged with heat.
In this case, it is preferable that the first flow divider be a gas-liquid separator.

In the refrigeration cycle, the discharge port of the two-stage compression compressor is connected to the condenser, the outlet of the condenser is connected to a second flow divider, and one of the second flow dividers is connected. An outlet is connected to a first expansion device, an outlet of the first expansion device is connected to the refrigerating compartment evaporator, and an outlet of the refrigerating compartment evaporator is passed through the refrigerating compartment side suction pipe to the two-stage compression. Connected to the intermediate pressure side suction port of the compressor, and connecting the other outlet of the second flow divider to the second expansion device,
The outlet of the second expansion device is connected to the freezer compartment cooler, and the outlet of the freezer compartment cooler is connected to the low pressure side inlet of the two-stage compression compressor via the freezer compartment side suction pipe. Preferably, the refrigerating compartment side suction pipe and the freezing compartment side suction pipe are heat-exchanged.

Furthermore, it is an even more preferable structure to use a hydrocarbon type refrigerant as the refrigerant.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. The same components as those of the conventional configuration (see FIG. 4) are designated by the same reference numerals. First, FIG. 2 is a vertical side view schematically showing the overall configuration of the refrigerator of this embodiment. As shown in FIG. 2, the main body 21 of the refrigerator of the present embodiment is composed of a heat insulating box, and a heat insulating partition wall 22 is integrally formed at an inner middle portion thereof. The heat insulating partition wall 22 sets different temperature spaces in the upper and lower portions of the refrigerator main body 21.

A refrigerating compartment 23 and a vegetable compartment 24 are vertically formed in the upper space of the heat insulating partition wall 22 in the refrigerator body 1. Further, two freezing chambers 25 and 26 are vertically formed in a space below the heat insulating partition wall 22. Each of these rooms 2
The front surfaces of 3 to 26 are configured to be opened and closed by the doors 27 to 30.

A refrigerator compartment evaporator chamber 31 is formed at the back of the vegetable compartment 24, and the refrigerator compartment evaporator chamber 3 is formed.
A refrigerating compartment evaporator 5 is arranged in the lower part of the inside of the inside 1, and a refrigerating compartment circulation fan 32 is arranged in the upper part.
The refrigerating room circulation fan 32 is configured such that the rotation speed can be variably controlled by an inverter, for example. In addition, a cold air duct 33 is provided on the rear surface of the refrigerating chamber 23.
Is provided, and a plurality of air outlets 33a are formed in the cold air duct 18.

On the other hand, the freezer compartment evaporator chamber 34 is formed in the inner part of the freezer compartments 25 and 26, and the freezer compartment evaporator 9 is arranged in the lower part of the freezer compartment evaporator room 34. At the same time, the circulation fan 35 for the freezer compartment is arranged in the upper part. This freezer compartment circulation fan 35 is configured such that the rotation speed can be variably controlled by an inverter, for example.

In the lower part of the refrigerator body 21, the machine room 3
6 is formed, and the two-stage compression compressor 2 and the condenser 3 are arranged in the machine chamber 36. And
The two-stage compression compressor 2 is configured so that the rotation speed can be variably controlled by an inverter, for example.

Next, the refrigeration cycle incorporated in the refrigerator will be described with reference to FIG. As shown in FIG. 1, in the refrigerating cycle 37 of the refrigerator,
The high-pressure side discharge port 2a of the two-stage compression compressor 2 is connected to the condenser 3
And the outlet of the condenser 3 is connected to the first expansion device 4, and the outlet of the first expansion device 4 is connected to the refrigerator compartment evaporator 5.
And the outlet of the refrigerator compartment evaporator 5 is connected to a gas-liquid separator (first flow divider) 6. The first diaphragm device 4 is composed of, for example, a capillary tube.

Then, one outlet of the gas-liquid separator 6 is connected to the intermediate pressure side suction port 2b of the two-stage compression compressor 2 through the R suction pipe (refrigerating chamber side suction pipe) 7. The other outlet of the gas-liquid separator 6 is connected to the second expansion device 8, the outlet of the second expansion device 8 is connected to the freezer compartment evaporator 9, and the freezer compartment evaporator 9 is connected. Outlet F suction pipe (suction pipe on the freezer side) 1
Low-pressure side suction port 2 of the two-stage compression compressor 2
connected to c. The second expansion device 8 is composed of, for example, a capillary tube.

Further, in this embodiment, the refrigerant in the R suction pipe 7 and the refrigerant in the F suction pipe 10 are heat-exchanged. Specifically, the two pipes 7 and 10 are arranged adjacent to each other for a predetermined length and are joined by, for example, soldering (see a portion surrounded by a chain double-dashed line in FIG. 1). As a result, the refrigerant discharged from the refrigerator compartment evaporator 5 and the refrigerant discharged from the freezer compartment evaporator 9 are heat-exchanged.

The R suction pipe 7 and the F suction pipe 10 may be joined by a brazing method other than the above-mentioned soldering, or they may be joined by an adhesive or the like.
Further, the heat exchange between the refrigerant in the R suction pipe 7 and the refrigerant in the F suction pipe 10 may be realized by using an appropriate heat exchanger or the like.

According to the refrigerating cycle 37 having the above-described structure, the set temperatures of the refrigerator compartment evaporator 5 and the freezer compartment evaporator 9 are set in the same manner as the conventional refrigerating cycle 1 (see FIG. 4). Each can be set quite freely and each evaporator 5, 9 can be cooled continuously. Therefore, the efficiency of the refrigeration cycle 37 can be increased, and the set temperature of the refrigerator compartment evaporator 5 is increased (for example, to about -1 to 0 ° C).
Because it becomes possible to set, the refrigerator 5 evaporator 5
It is possible to reduce the amount of frost formed on the refrigerator compartment and keep the humidity in the refrigerator compartment 23 and the vegetable compartment 24 high.

In the refrigeration cycle 37, if an excessive load is applied only to the freezer compartments 25 and 26, it becomes difficult for the refrigerant to flow in the evaporator 9 for the freezer compartment and the refrigerating capacity becomes insufficient. The control is performed by increasing the rotation speed of the compressor 2. And if you respond like this,
The cooling capacity becomes excessive in the refrigerating compartment 23, and the proportion of the liquid refrigerant in the refrigerant discharged from the refrigerating compartment evaporator 5 increases,
The liquid refrigerant that has not been phase-separated in the gas-liquid separator 6 comes to flow through the R suction pipe 7.

That is, the two-phase refrigerant flows in the R suction pipe 7. Therefore, liquid return to the intermediate pressure side suction port 2b of the two-stage compression compressor 2 or dew condensation on the R suction pipe 7 may occur.

On the other hand, in the above embodiment, the refrigerant discharged from the refrigerator compartment evaporator 5 and the refrigerant discharged from the freezer compartment evaporator 9 are heat-exchanged (specifically, R Since the suction pipe 7 and the F suction pipe 10 are arranged adjacent to each other by a predetermined length and are joined by soldering, even if the refrigerant cannot be completely evaporated in the refrigerator compartment evaporator 9, the R suction The gas refrigerant in the F suction pipe 10 can be cooled by the two-phase refrigerant flowing in the pipe 7, and the liquid refrigerant flowing in the R suction pipe 7 can be evaporated. This allows
The refrigerant density of the low pressure side suction port 2c of the two-stage compression compressor 2 can be increased.

As a result, the refrigerant flow rate of the freezer compartment evaporator 9 can be increased and the cooling capacity of the freezer compartments 25 and 26 can be increased. Therefore, according to the above-described embodiment, it is possible to prevent liquid return to the intermediate pressure side suction port 2b of the two-stage compression compressor 2 and dew condensation of the R suction pipe 7.

FIG. 3 is a block diagram of a refrigeration cycle showing a second embodiment of the present invention. The same components as those of the conventional configuration (see FIG. 5) and the first embodiment (see FIG. 1) are designated by the same reference numerals.

In the refrigeration cycle 38 of the second embodiment, as shown in FIG. 3, the high pressure side discharge port 2a of the two-stage compression compressor 2 is connected to the condenser 3, and the outlet of this condenser 3 is diverted. It is connected to the container (second shunt) 12. Then, one outlet of this flow divider 12 is connected to the first expansion device 4
The outlet of the first expansion device 4 is connected to the refrigerator compartment evaporator 5, and the outlet of the refrigerator compartment evaporator 5 is connected to the intermediate pressure side suction port of the two-stage compression compressor 2 via the R suction pipe 7. It is connected to 2b.

The other outlet of the flow divider 12 is connected to the second expansion device 8, the outlet of the second expansion device 8 is connected to the evaporator 9 for the freezing compartment, and the cooler 9 for the freezing compartment is connected. At the outlet of the two-stage compression compressor 2 through the F suction pipe 10
Is connected to the low pressure side suction port 2c.

Further, also in the second embodiment, similar to the first embodiment, the R suction pipe 7 and the F suction pipe 10 are arranged adjacent to each other by a predetermined length and are joined by soldering. . That is, the refrigerant in the R suction pipe 7 and the refrigerant in the F suction pipe 10 are heat-exchanged.

The structure of the second embodiment other than the above is the same as the structure of the first embodiment. Therefore, also in the second embodiment, it is possible to obtain substantially the same operational effects as in the first embodiment.

In each of the above embodiments, a CFC-based refrigerant such as R134a is used as the refrigerant, but a hydrocarbon-based refrigerant such as R600a may be used instead.

[0036]

As is apparent from the above description, the present invention relates to a refrigerator in which a refrigerating cycle having a two-stage compression compressor is incorporated, and a refrigerant discharged from a refrigerating compartment evaporator and a refrigerating compartment evaporator. Since it is configured to exchange heat with the refrigerant that comes out, if an excessive load is applied to the freezer,
It has an excellent effect that it is possible to prevent liquid return to the suction port on the intermediate pressure side of the two-stage compression compressor and dew condensation on the suction pipe for the refrigerating room.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle showing a first embodiment of the present invention.

FIG. 2 is a schematic vertical sectional side view of a refrigerator.

FIG. 3 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional configuration.

FIG. 5 is a view corresponding to FIG. 1 showing another conventional configuration.

[Explanation of symbols]

1 is a refrigeration cycle, 2 is a two-stage compression compressor, 2a is a high-pressure side discharge port, 2b is an intermediate-pressure side suction port, 2c is a low-pressure side suction port, 3 is a condenser, 5 is a refrigerator evaporator, and 6 is gas-liquid. Separator (first flow divider), 7 R suction pipe (refrigerator side suction pipe), 9 freezer evaporator, 10 F
Suction pipe (suction pipe on the freezer side), 11
Is a refrigeration cycle, 12 is a flow divider, 21 is a main body, 23 is a refrigerating compartment, 24 is a vegetable compartment, 25 and 26 are freezing compartments, 32 is a refrigerating compartment circulation fan, 35 is a freezing compartment circulation fan, and 37 is a refrigeration cycle. , 38 indicates a refrigeration cycle.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Kashima             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory

Claims (5)

[Claims] 1. A refrigeration cycle including a two-stage compression compressor having a low-pressure side suction port and an intermediate-pressure side suction port, a condenser, a refrigerator compartment evaporator, and a freezer compartment evaporator. In the refrigerator, the refrigerant discharged from the refrigerator evaporator and the refrigerant discharged from the freezer evaporator are heat-exchanged. 2. In the refrigeration cycle, the outlet of the two-stage compression compressor is connected to the condenser, the outlet of the condenser is connected to a first expansion device, and the outlet of the first expansion device is connected. It is connected to the refrigerating compartment evaporator, an outlet of the refrigerating compartment evaporator is connected to a first flow divider, and one outlet of the first flow divider is passed through the refrigerating compartment side suction pipe to the two-stage compression. Connected to the intermediate pressure side suction port of the compressor,
The other outlet of the shunt is connected to the second expansion device, and the outlet of the second expansion device is connected to the freezer evaporator.
The evaporator of the freezer compartment is connected to the low pressure side suction port of the two-stage compression compressor via the freezer compartment suction pipe, and the refrigerating compartment side suction pipe and the freezer compartment side suction pipe are heat-exchanged. The refrigerator according to claim 1, wherein the refrigerator is configured to operate. 3. The refrigerator according to claim 2, wherein the first flow divider comprises a gas-liquid separator. 4. In the refrigeration cycle, the outlet of the two-stage compression compressor is connected to the condenser, the outlet of the condenser is connected to a second flow divider, and one of the second flow dividers is connected. An outlet is connected to a first expansion device, an outlet of the first expansion device is connected to the refrigerating compartment evaporator, and an outlet of the refrigerating compartment evaporator is passed through the refrigerating compartment side suction pipe to the two-stage compression. Connected to the suction port on the intermediate pressure side of the compressor,
The other outlet of the shunt is connected to the second expansion device, and the outlet of the second expansion device is connected to the freezer evaporator.
The evaporator of the freezer compartment is connected to the low pressure side suction port of the two-stage compression compressor via the freezer compartment side suction pipe, and the refrigeration room side suction pipe and the freezer compartment side suction pipe are heat-exchanged. The refrigerator according to claim 1, wherein the refrigerator is configured to operate. 5. The refrigerator according to claim 1, wherein a hydrocarbon refrigerant is used as the refrigerant.