JPH08121885A - Refrigerator - Google Patents

Abstract

PURPOSE: To prevent the decrease in refrigerating capacity due to the retention of refrigerating machine oil in an evaporator and the decrease in lubricity due to lack of supply oil to a compressor sliding part in a refrigerator using non-compatible refrigerant and the oil. CONSTITUTION: A channel branch vessel 4 is disposed between a dryer 3 and a capillary tube 5 in a refrigerating cycle. Refrigerating machine oil discharged together with refrigerant from a compressor 1 and fed to a condenser 2, the dryer 3 and the vessel 4 is shut off by a filter 10 installed in the vessel and the liquid refrigerant of the lower layer of separated two layers, retained at the center of the vessel, and returned to the compressor 1 from an oil discharge pipe 7a by opening a switching valve 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator using a refrigerant having a low mutual solubility and a refrigerating machine oil, and lowering the refrigerating capacity due to the accumulation of the refrigerating machine oil in the evaporator and supplying oil to a sliding portion of the compressor. In order to reduce the deterioration of lubrication characteristics due to a shortage and to accelerate the cooling effect of the compressor, the refrigerating machine oil that has flowed into the refrigeration cycle from the compressor together with the refrigerant does not flow into the evaporator The present invention relates to a refrigerator in which a refrigerating cycle is configured to be returned to.

[0002]

2. Description of the Related Art Among refrigerants used in conventional refrigerators, a refrigerant containing chlorine, for example, CFC-12, causes an iron chloride film to form on a sliding portion of a compressor due to the action of chlorine, resulting in extreme pressure action. Therefore, there is an advantage that the lubrication characteristics can be improved.
On the other hand, CFCs currently released into the atmosphere on the earth, especially C
FC-11, CFC-12, CFC-113, CFC-
114, CFC-115 and the like have a medical and environmental problem, because the unique properties of the refrigerant destroy the ozone layer in the atmosphere and increase the amount of ultraviolet rays reaching the earth's surface. At present, it is required to switch to a refrigerator using a refrigerant such as HFC-134a having a low ozone depletion coefficient as an alternative refrigerant to the refrigerant CFC-12. However, when the refrigerant HFC-134a is used in the refrigeration cycle of the refrigerator, since the refrigerant does not contain chlorine,
As compared with the refrigerant CFC-12, there is a problem that the lubrication characteristics are deteriorated and the sliding parts of the compressor are worn.

Mineral oil or the like generally used as a refrigerating machine oil for the refrigerant CFC-12 is a refrigerant HFC-134a.
As a refrigerating machine oil for the refrigerant HFC-134a, ester oil having mutual solubility is generally listed as a candidate because it has low mutual solubility. However, ester oil has a high hygroscopic property and is due to hydrolysis of oil. It is necessary to deal with sludge generation, deterioration of abrasion resistance of the sliding parts of the compressor, etc., to remove water and contaminants during the refrigeration cycle, and to change the material of the sliding parts of the compressor. There is a problem of increase. On the other hand, when a non-ester oil having no mutual solubility is used as the refrigerating machine oil for the refrigerant HFC-134a,
Because the refrigerating machine oil that has flowed into the refrigerating cycle from the compressor and separated into two layers stays in the evaporator at low temperature and heat exchange performance deteriorates, or the amount of refrigerating machine oil in the compressor is insufficient. There is a problem that lubrication characteristics deteriorate due to insufficient oil supply to the sliding parts of the compressor.

At present, there is JP-A-5-157379 as an example in which the above-mentioned problems are studied in a refrigerator using a refrigerant HFC-134a. An example of the configuration of the refrigerating cycle will be described with reference to FIG. , Condenser 2,
In a refrigeration cycle in which a dryer 3, a capillary tube 5, an evaporator 6, and a refrigerant liquid accumulator 41 are annularly connected to each other by a pipe 7, a non-ester system having a low mutual solubility with a refrigerant HFC-134a as refrigerating machine oil. Using hard alkyl benzene oil,
The deterioration of abrasion resistance and sludge formation are improved as compared with the case of using ester oil. Further, as means for accelerating the return of the refrigerating machine oil that has flowed into the refrigeration cycle to the compressor, an evaporator 6 is provided above the accumulator 41.
Connect the outlet side, connect the compressor 1 suction side to the lower side,
By inserting the suction pipe into the accumulator 41 and extending it upward, the refrigerant and the oil flowing into the accumulator 41 are separated into two layers, and the oil in the upper layer flows from the suction pipe inlet to the suction side of the compressor 1. The structure is such that it returns to prevent accumulation of refrigerating machine oil in the accumulator 41.
Further, the viscosity of the oil is lowered to secure the low temperature fluidity of the oil in the evaporator 1, and the amount of oil adhering to the inner wall of the evaporator 1 is suppressed to prevent the heat exchange performance from deteriorating. Further, the oil discharge amount of the compressor 1 is reduced.

As described above, Japanese Patent Application Laid-Open No. 5-15733 / 1993
According to Japanese Patent Publication No. 79, in a refrigerator using a refrigerant HFC-134a, a non-ester oil having a low mutual solubility is used as a refrigerating machine oil, and the refrigerating machine oil flowing into the refrigeration cycle is returned to the compressor without being retained in the cycle. Therefore, the cycle components have been improved to reduce the deterioration of the refrigeration capacity due to insufficient oil supply to the sliding parts of the compressor and oil retention in the evaporator.

[0006]

[Problems to be Solved by the Invention]
According to Japanese Patent Publication No. 9, in a refrigerator using a refrigerant HFC-134a, a non-ester oil having a low mutual solubility is used as a refrigerating machine oil, and an oil return to a compressor is promoted mainly by improving cycle components. However, the accumulation of refrigerating machine oil in the accumulator can be reduced, but the refrigerating machine oil inevitably accumulates in the evaporator to some extent, and the problem that the heat transfer coefficient of the evaporator is deteriorated and the refrigerating capacity is reduced has been solved. Absent. Further, particularly in a rotary compressor, a roller that eccentrically rotates in the cylinder of the compressor to compress the refrigerant and a vane that divides the space partitioned by the cylinder and the roller into the refrigerant compression space while reciprocating Since the lubrication of the contact portion is likely to be boundary lubrication and the wear of the sliding portion is likely to occur, it is important to lower the temperature of the sliding portion in order to suppress this wear. Little consideration was given to the cooling of the moving part.

[0007]

[Means for Solving the Problems] As means for solving the above problems, (1) In the refrigerating cycle of a refrigerator using a refrigerant having a low mutual solubility and refrigerating machine oil, in the middle of piping between a dryer and a capillary tube. A flow path branch container is disposed in the flow path branch container so that the flow of the refrigerating machine oil is circulated through the compressor, the condenser, the dryer, the flow path branching container, and the compressor. Configure the refrigeration cycle to return to the compressor without going through a tube and evaporator,
Oil supply to the sliding parts of the compressor and cooling of the compressor are promoted, and refrigerating machine oil is prevented from accumulating in the evaporator.

(2) A refrigerating machine oil is compressed through the on-off valve by providing an on-off valve in the middle of the oil discharge pipe protruding from the flow path branch container and intermittently opening and closing the on-off valve during operation of the compressor. The refrigeration cycle is configured to return to the cabin.

(3) Of the upper-layer side refrigerating machine oil and the lower-layer side liquid refrigerant which flow into the flow path branching container from the condenser and are separated into two layers, the upper layer is when the on-off valve is closed during the operation of the compressor. Refrigerator oil on the side is stored inside the flow path separation container,
The refrigeration cycle is configured to return to the inside of the compressor via the opening / closing valve when the opening / closing valve is open.

(4) During operation of the compressor, when the on-off valve is closed, the upper-layer side refrigerating machine oil separated into two layers in the flow passage branch container overflows from the flow passage separation container and enters the condenser. In order to prevent the inflow, the internal volume of the flow path separation container is ensured to be equal to or larger than the upper limit amount of refrigerating machine oil accumulated in the container.

(5) An oil passage capillary tube is provided in the middle of the pipe corresponding to the oil return flow passage between the oil discharge pipe and the compressor, and the oil is passed from the condenser into the flow passage branch container to separate into two layers. The flow resistance of the oil passage capillary tube is set so that the refrigerating machine oil on the upper layer side is directly returned into the compressor through the oil discharge pipe.

(6) A filter that separates the gas refrigerant from the refrigerating machine oil and allows only the gas refrigerant to pass through is installed above the protruding position of the oil discharge pipe in the internal space of the flow path branching container. The gas refrigerant discharge pipe is projected from above the filter position, and is connected to the middle of the pipe between the flow path branch container and the capillary tube by a pipe.

(7) The gas refrigerant in the flow path branch container is allowed to flow from the filter through the gas refrigerant discharge pipe into the evaporator through the gas refrigerant discharge pipe without returning to the compressor through the oil discharge pipe. The flow resistance of the capillary tube between the flow path branch container and the evaporator and the flow resistance of the oil passage capillary tube or the on-off valve between the flow path branch container and the compressor are set.

(8) In a refrigerating cycle of a refrigerator equipped with a rotary compressor, an oil return passage is constituted so as to directly return refrigerating machine oil into a compressor cylinder through an oil discharge pipe, and in a refrigerant compression process. Intake refrigeration oil into the cylinder.

(9) In a refrigeration cycle of a refrigerator equipped with a reciprocating compressor, an oil return flow path is constructed so that refrigerating machine oil is returned directly to the middle of the compressor suction pipe or directly into the compressor chamber via the oil discharge pipe. To do. In particular, when an S tank is provided in the middle of the pipe between the evaporator and the compressor, the refrigerating machine oil is returned immediately before the S tank.

[0016]

In the conventional refrigeration cycle, the refrigerating machine oil that has flowed into the refrigerating cycle from the compressor together with the refrigerant tends to stay in the evaporator where the oil viscosity increases due to the low temperature, and the refrigerating machine oil adheres to the inner wall of the evaporator and heats up. Since the transmissivity is reduced and the endothermic effect is reduced, the refrigerating capacity is reduced. Further, since the amount of refrigerating machine oil in the compressor is insufficient due to the accumulation of refrigerating machine oil in the cycle, insufficient supply of oil to the sliding parts of the compressor causes wear of the sliding parts. In a refrigerator using a refrigerant and a refrigerating machine oil having low mutual solubility, it is expected that improvement of the cycle components as shown in Fig. 4 is still insufficient for solving these problems. However, according to the present invention,
By installing a flow path branching container equipped with an oil return mechanism in the middle of the pipe between the dryer and the capillary tube, the flow of refrigerating machine oil into the evaporator is almost prevented during compressor operation, and refrigerating machine oil is compressed. Since the compressor oil can be efficiently returned to the inside of the machine and the cooling of the compressor is promoted by the refrigerating machine oil cooled by the condenser, the above problems can be solved.

Refrigerant and refrigerating machine oil having a low mutual solubility flowing from the compressor into the refrigeration cycle flow into the flow path branch container after passing through the condenser, and the liquid refrigerant condensed by the condenser is directed to the lower layer side. , Refrigerating machine oil is separated into two layers on the upper layer side. A small amount of gas refrigerant that has not been completely condensed by the condenser accumulates on the upper layer side of the refrigerating machine oil.

An on-off valve is provided in the middle of the oil discharge pipe protruding from the flow path branching container to intermittently open and close the valve during operation of the compressor, and when the valve is closed, the refrigerating machine oil on the upper layer side is supplied. Stored inside the flow path separation container, and when the valve is open,
It is discharged from the oil discharge pipe and returned directly into the compressor via the on-off valve.

Further, an oil passage capillary tube is provided in the middle of the pipe corresponding to the oil return passage between the oil discharge pipe and the compressor, and the upper layer separated from the condenser into the passage branch container is separated into two layers. The flow resistance of the oil passage capillary tube is set so that the refrigerating machine oil on the side is returned directly into the compressor via the oil discharge pipe.

A filter for separating the gas refrigerant and the refrigerating machine oil and allowing only the gas refrigerant to pass therethrough is installed above the protruding position of the oil discharge pipe in the internal space of the flow path branching container, and the filter of the flow path branching container is further provided. The gas refrigerant discharge pipe is projected from above the position and connected by a pipe halfway between the flow path branch container and the capillary tube, and a small amount of gas refrigerant accumulated in the upper layer of the refrigerating machine oil is passed through the filter to pass through the gas refrigerant. Flow from the capillary tube into the evaporator through the discharge pipe. On the other hand, the refrigerating machine oil is not blocked by the filter and flows into the gas refrigerant discharge pipe, and is returned directly into the compressor through the oil discharge pipe. In addition, the flow resistance of the capillary tube between the flow path branch container and the evaporator and the oil between the flow path branch container and the compressor are adjusted so that the gas refrigerant does not return into the compressor through the oil discharge pipe together with the refrigeration oil. Set the flow resistance ratio of the passing capillary tube.

As a result of the above operation, the liquid refrigerant in the flow path branch container accumulates at the bottom of the flow path branch container and flows into the evaporator through the capillary tube, and the gas refrigerant in the flow path branch container is frozen. Refrigerant machine oil in the flow path branch container collects in the upper layer of machine oil and permeates the filter, then flows into the evaporator through the gas refrigerant discharge pipe and the capillary tube, and is stored in the container between the liquid refrigerant and the gas refrigerant. When it collects in the central portion and the on-off valve opens, it flows into the compressor through the oil discharge pipe and the oil passage capillary tube. Therefore, the refrigerating machine oil can be prevented from flowing into the evaporator and returned to the compressor, and the refrigerant can be prevented from flowing directly from the condenser into the compressor and allowed to flow into the evaporator.

As a result, the refrigerating capacity can be improved by preventing the refrigerating machine oil from staying in the evaporator. Further, it is possible to secure sufficient oil supply to the sliding portion of the compressor, prevent deterioration of lubricity, and improve reliability. Moreover, especially in the case of a refrigeration cycle using a rotary compressor,
By supplying the refrigerating machine oil cooled in the condenser into the cylinder of the compressor during the refrigerant compression process, the cooling effect of the compressor can be obtained.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

1 to 3 are refrigeration cycle system diagrams of the refrigerator of the present invention. FIG. 1 shows a refrigerator equipped with a rotary compressor, and FIGS. 2 to 3 show a refrigeration cycle equipped with a reciprocating compressor. Show.

In FIG. 1, the refrigerant and the refrigerating machine oil are HFC-134a and non-ester type refrigerating machine oil, which have low mutual solubility, and the refrigerant HFC-134a is the compressor 1
Is compressed by the compressor and discharged as high-temperature and high-pressure gas.
Is condensed and liquefied, the moisture in the refrigerant is absorbed by the dryer 3, and the moisture flows into the flow path branch container 4. Here, the liquid refrigerant is separated into two layers from the refrigerating machine oil, and is accumulated in the lower layer side, that is, at the bottom of the flow path branching container 4, and flows into the capillary tube 5, and the gas refrigerant is separated into two layers from the liquid refrigerant and the upper layer side refrigerating machine oil is separated. Permeate the filter 10 from above and flow into the capillary tube 5 through the gas refrigerant discharge pipe 7b. The refrigerant flowing into the capillary tube 5 is decompressed and evaporated in the evaporator 6,
The gas is vaporized into a low temperature and low pressure gas, which is sucked into the compressor 1 and recompressed, and the above cycle is repeated. On the other hand, the non-ester type refrigerating machine oil is discharged together with the refrigerant from the compressor 1, passes through the condenser 2 and the drier 3, and is passed through the flow path branching container 4
Flows into. Here, the refrigerating machine oil is separated into two layers from the liquid refrigerant, and is collected in the upper layer side, that is, in the center of the container, and is sucked into the oil discharge pipe 7a when the opening / closing valve 11 is opened during the operation of the compressor and the oil passage capillary tube. It flows into the cylinder of the compressor 1 via 9 in the refrigerant compression process. Since the refrigerating machine oil in the flow path branch container 4 is blocked by the filter 10 at the upper side and by the liquid refrigerant at the lower side, the evaporator 6 is blocked.
Inflow to the inside can be almost prevented. Further, the flow path branching container 4 is provided so that refrigeration oil in the flow path branching container 4 does not overflow from the container.
By setting the internal volume of the refrigerating machine oil, it is possible to prevent the refrigerating machine oil from flowing into the condenser 2 when the on-off valve 11 is closed.
In addition, each element which comprises the said refrigeration cycle is hermetically connected by the suitable piping 7, respectively.

The oil return passage 8 to the compressor 1 may be connected to the compressor suction 7c, but in this case, the volume efficiency of the compressor 1 is lowered due to the temperature rise of the suction gas refrigerant. In the present embodiment, the oil return passage 8 is connected to the main bearing in the compressor 1, and is opened to a position opened and closed by the end surface portion of the roller that eccentrically rotates in the cylinder to compress the refrigerant, The timing of opening the flow path was during the compression of the gas refrigerant by the rotation of the roller. Accordingly, the gas refrigerant being compressed and the sliding portion of the compressor 1 can be cooled by the refrigerating machine oil without lowering the volumetric efficiency of the compressor 1, and the refrigerating machine oil discharged into the cylinder is
It also contributes to improving the lubricity of the contact area between the roller and the vane. The on-off valve 11 can be omitted by adjusting the flow resistance of the oil passage capillary tube 9.

According to the above-described embodiment, it is possible to prevent the refrigerating machine oil from flowing into the evaporator during the operation of the compressor, and to compensate the deterioration of the refrigerating capacity due to the decrease of the heat exchange amount of the evaporator.
In addition, by returning the refrigerating machine oil that has flowed into the cycle during operation of the compressor to the compressor without passing through the evaporator, it is possible to secure the amount of refrigerating machine oil in the compressor and promote lubrication to the sliding parts of the compressor. Let Further, by returning the refrigerating machine oil to the inside of the compressor cylinder during the refrigerant compression process, it is possible to prevent deterioration of lubricity of the contact portion between the roller and the vane, and improve the compressor volume efficiency. Further, the cooling of the compressor is promoted by returning the refrigerating machine oil cooled by the condenser into the compressor. Therefore, the reliability of the compressor can be improved.

When the present invention is applied to a refrigerator equipped with a reciprocating compressor, it is not possible to obtain the cooling effect of the compressor as in the case of the rotary compressor, but the refrigerating machine oil is prevented from accumulating in the evaporator. By doing so, it is possible to improve the wear resistance by preventing the deterioration of the refrigerating capacity, securing the necessary refrigerating machine oil in the compressor, and promoting the oil supply to the sliding parts of the compressor.

FIG. 2 shows the oil return flow path 8 through the oil discharge pipe 7 in the refrigeration cycle of the refrigerator equipped with the reciprocating compressor.
Compressor 1 from a through the oil passage capillary tube 9
This is an example in which it is connected to the inside of the chamber, and the cycle configuration of the other parts conforms to FIG.

FIG. 3 shows an oil return flow path 8 through an oil discharge pipe 7 in a refrigeration cycle of a refrigerator equipped with a reciprocating compressor.
By connecting from a to the compressor suction pipe 7c via the oil passage capillary tube 9, the refrigerating machine oil accumulated in the flow path branch container 4 due to the suction pressure of the compressor suction pipe 7c is promptly transferred to the compressor 1. Can be returned. The cycle configuration of the other parts conforms to FIG.

However, in the case of a refrigerator equipped with the reciprocating compressor shown in FIGS. 2 and 3, regarding the capillary tube 5 and the oil passage capillary tube 9, the oil passage capillary tube 9 is changed by changing the inner diameter and the length. The on-off valve 11 can be omitted by increasing the flow resistance of the above and adjusting the flow rates of the refrigerant and the refrigerating machine oil.

In the embodiment described here, HFC-134 having a low mutual solubility as a refrigerant and a refrigerating machine oil is used.
The present invention relates to a refrigerator using a and a non-ester type refrigerating machine oil. The present invention relates to HCFC-22 and R502.
Similar effects can be obtained even when applied to a refrigerator using a mixed refrigerant which is an alternative refrigerant and a non-ester type refrigerating machine oil.

[0033]

As described above, according to the present invention, in order to prevent deterioration of refrigerating capacity due to retention of refrigerating machine oil in the evaporator and deterioration of lubricating characteristics due to insufficient oil supply to the sliding parts of the compressor,
The refrigeration cycle is configured so that the refrigeration oil discharged from the compressor into the refrigeration cycle together with the refrigerant is returned to the compressor without flowing into the evaporator.A flow path is provided in the middle of the pipe between the dryer and the capillary tube. By disposing the branching container and returning the refrigerating machine oil to the compressor without passing through the evaporator, the refrigerating capacity can be improved by preventing the refrigerating machine oil from staying in the evaporator. In addition, it is possible to secure the amount of oil in the compressor, sufficiently supply the oil to the sliding portion, improve the lubricity, and improve the reliability of the compressor and the refrigeration system as a whole. Further, in the refrigerator employing the rotary compressor, in addition to the above effects, the cooling effect of the compressor can be obtained, and the abrasion resistance of the compressor sliding portion can be improved to further improve the reliability. .

[Brief description of drawings]

FIG. 1 is a system diagram of a refrigeration cycle of the present invention equipped with a rotary compressor.

FIG. 2 is a system diagram of a refrigeration cycle of the present invention equipped with a reciprocating compressor.

FIG. 3 is a system diagram of a refrigeration cycle of the present invention equipped with a reciprocating compressor.

FIG. 4 is a system diagram of a conventional refrigeration cycle.

[Explanation of Codes] 1 ... Compressor, 2 ... Condenser, 3 ... Dryer, 4 ... Flow path branch container, 5 ... Capillary tube, 6 ... Evaporator, 7 ... Piping, 7a ... Oil discharge pipe, 7b ... Gas refrigerant Discharge pipe, 7c ... Compressor suction pipe, 8 ... Oil return flow passage, 9 ... Oil passage capillary tube, 10 ... Filter, 11 ... Open / close valve, 41 ... Accumulator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuko Yoshinaga 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Living Equipment Division, Hitachi, Ltd. Address No. 2 within Hitachi Tochigi Electronics Co., Ltd. (72) Inventor, Yoshihiko Gonmori 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Living Equipment Division, Hitachi Ltd.

Claims (10)

[Claims] 1. A compressor, a condenser, a dryer, a capillary tube, and an evaporator are connected in a ring shape by pipes, and in a refrigerating cycle of a refrigerator using a refrigerant and a refrigerating machine oil having a low mutual solubility, the dryer and the capillary are used. A flow path branching container is arranged in the middle of the pipe between the tubes, and the flow path of the refrigerant is flown by the compressor, the condenser, the dryer, the flow path branching container, the capillary tube, the evaporator, and the compression unit. A refrigerator characterized in that a refrigerating cycle is configured so that a flow of refrigerating machine oil is circulated through a compressor, a condenser, a dryer, the flow path branching container, and the compressor, while being circulated with a machine. 2. An on-off valve is provided in the middle of an oil discharge pipe projecting from the flow path branching container, and the on-off valve is opened and closed intermittently during operation of a compressor to allow refrigerating machine oil to pass through the on-off valve. The refrigerator according to claim 1, wherein the refrigeration cycle is configured to be returned to the inside of the compressor by means of a refrigerator. 3. Of the refrigerating machine oil on the upper layer side and the liquid refrigerant on the lower layer side, which flow into the flow path branching container from the condenser and are separated into two layers, when the on-off valve is closed during operation of the compressor. Refrigerating machine oil on the upper layer side is stored inside the flow path separation container, and the refrigerating machine oil on the upper layer side stored inside the flow path separation container is compressed through the opening / closing valve when the opening / closing valve is open. The refrigerator according to claim 1 or 2, wherein the refrigeration cycle is configured to be returned to the inside of the machine. 4. The upper layer refrigerating machine oil out of the upper layer refrigerating machine oil and the lower layer side liquid refrigerant flowing from the condenser into the channel branching vessel and separated into two layers overflows from the channel separating vessel. The refrigerator according to claim 1, 2, or 3, wherein an internal volume of the flow path separation container is secured so as not to exist. 5. An oil passage capillary tube is provided in the middle of a pipe corresponding to an oil return flow passage between the oil discharge pipe and the compressor, and the oil is passed through the condenser into the flow passage branch container to separate into two layers. Of the upper layer side refrigerating machine oil and the lower layer side liquid refrigerant, the flow rate resistance of the oil passage capillary tube was set so as to directly return the upper layer side refrigerating machine oil into the compressor through the oil discharge pipe. The refrigerator according to claim 1, wherein the refrigerator is a refrigerator. 6. A filter for separating the gas refrigerant and the refrigerating machine oil and allowing only the gas refrigerant to pass through is installed above the protruding position of the oil discharge pipe in the internal space of the flow path branching container, and the flow path branching is further provided. The gas refrigerant discharge pipe is projected from above the filter position of the container, and is connected by a pipe to a midway of the pipe between the flow path branch container and the capillary tube. Refrigerator described. 7. A small amount of gas refrigerant, which is not completely condensed in a condenser and is accumulated in the upper layer of refrigerating machine oil separated into two layers in the flow path branch container, returns to the compressor through the oil discharge pipe. Instead, to flow from the filter through the gas refrigerant discharge pipe into the evaporator from the capillary tube,
The flow resistance of the capillary tube between the flow path branch container and the evaporator, and the flow resistance of the oil passage capillary tube or the on-off valve between the flow path branch container and the compressor are set. The refrigerator according to any one of claims 1 to 6. 8. In a refrigeration cycle of a refrigerator equipped with a rotary compressor, an oil return passage is constituted by piping so as to return the refrigerating machine oil directly into a compressor cylinder during a compression process through an oil discharge pipe. The refrigerator according to claim 1, wherein the refrigerator is a refrigerator. 9. In a refrigeration cycle of a refrigerator equipped with a reciprocating compressor, an oil return flow path is constituted by piping so as to directly return refrigerating machine oil into the compressor suction pipe or the compressor chamber via the oil discharge pipe. The refrigerator according to claim 1, wherein the refrigerator is used. 10. HFC-1 which is a CFC-12 alternative refrigerant.
34a or a refrigerating cycle of a refrigerator using a mixed refrigerant which is a substitute refrigerant for HCFC-22 and R502 and a non-ester type refrigerating machine oil, wherein the flow path branching container is arranged. The refrigerator according to item 1.