JPH0886540A - Refrigeration system using HFC-based non-azeotropic refrigerant mixture - Google Patents

Abstract

(57) [Abstract] [Purpose] The composition of the refrigerant mixture during the refrigeration cycle can be reduced and stable over a long period of time even when using a non-flammable HFC-based non-azeotropic refrigerant mixture that does not risk the ozone layer Develop a refrigeration system that can be operated by In a refrigeration system including a condenser, a capillary tube, an evaporator, an accumulator, a compressor, and the like, and a HFC-based non-azeotropic refrigerant mixture as a refrigerant compressed by the compressor, a refrigerant pool of the accumulator is collected. It is characterized in that the accumulator is provided with a gasification chamber for vaporizing the liquid-phase refrigerant and mixing with the gas-phase refrigerant of the accumulator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture, and more specifically to a non-flammable HFC which does not have a risk of depleting the ozone layer.
The present invention relates to a refrigerating apparatus which can be stably operated for a long period of time because the composition change of the refrigerant mixture in the refrigeration cycle can be reduced even when a non-azeotropic refrigerant mixture is used.

[0002]

2. Description of the Related Art Dichlorodifluoromethane (R-12) and azeotrope mixed refrigerants R-12 and 1,1-difluoroethane (R-) have hitherto been used as refrigerants for refrigerators.
152a) and many R-500s. The boiling point of R-12 is −29.65 ° C. at atmospheric pressure, and the boiling point of R500 is −3.
3.45 ° C., suitable for ordinary refrigeration equipment, R-
Refrigeration cycles using refrigerating machine oils such as mineral oils and alkylbenzene oils that are compatible with CFC-based refrigerants such as 12 have reached high quality levels such as reliability and durability.

However, due to their high ozone depletion potential, each of the above refrigerants destroys the ozone layer when it reaches the ozone layer above the earth by being released into the atmosphere.
The destruction of the ozone layer is caused by chlorine groups (Cl) in the refrigerant. Therefore, a refrigerant having a low chlorine group content, for example, chlorodifluoromethane (HCFC-22,
R-22), chlorine-free refrigerants such as difluoromethane (HFC-32, hereinafter R-32), pentafluoroethane (HFC-125, hereinafter R)
-125) or 1,1,1,2-tetrafluoroethane (HFC-134a, hereinafter R-134a),
Alternatively, mixtures of these are considered as alternative refrigerants for these. The boiling point of R-22 is -40.
At 82 ° C., the boiling point of R-32 is −51.7 ° C. and R-1.
The boiling point of 25 is -48.5 ° C, and the boiling point of R-134a is
It is -26.5 degreeC.

The HFC-based refrigerant mixture is a mixture of HFC-based refrigerants.
It is a mixture of three or more kinds, and usually, there are many combinations in which the boiling point and the dew point of the mixture are different. In the present invention, these mixtures are referred to as HFC-based non-azeotropic refrigerant mixture. The HFC-based non-azeotropic refrigerant mixture is specifically, for example,
R125 / R143a / 134a (weight ratio 44/52 /
4) (R404A, boiling point -46.78 ° C, dew point -46.
08 ° C, trade name: HP62, manufactured by DuPont), R32 /
R125 / 134a (weight ratio 20/40/40) (R4
07A, boiling point -45.4 ° C, dew point -38.8 ° C, trade name: KLEA60G2, manufactured by ICI, hereinafter KLEA60.
Can be mentioned).

FIG. 4 shows an example of a typical refrigeration circuit. 1 is a compressor, 2 is a condenser, 3 is a dryer, 4 is a capillary tube, 5 is an evaporator, and 6 is an accumulator.
The arrow indicates the flow direction of the refrigerant. FIG. 5 is an enlarged cross-sectional explanatory view of a typical conventional accumulator 6. The arrow indicates the flow direction of the refrigerant. Since the refrigeration cycle using the HFC-based non-azeotropic refrigerant mixture is a non-azeotropic mixture, the composition of the refrigerant mixture changes at each part of the refrigeration cycle, and for example, the refrigerant 8 accumulated at the bottom of the accumulator 6 is a high boiling point component. Many,
The gas-phase refrigerant 9 above the accumulator 6 has many low-boiling components. Therefore, the refrigerant sucked into the compressor 1 through the gas-phase refrigerant outlet pipe 7 in the accumulator 6 becomes a refrigerant mixture having a large amount of low-boiling components, so that the refrigerating capacity and refrigerating capacity are not uniform and stable for a long period of time. It has the drawback of not being able to drive.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to use an HFC-based non-azeotropic refrigerant mixture which is non-flammable and has no risk of depleting the ozone layer, and a refrigerant mixture which is drawn into the compressor from the accumulator. It is to provide a refrigerating apparatus which has a uniform composition and can be stably operated over a long period of time.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies conducted by the inventor in view of the above-mentioned problems, as a result of providing the gasification chamber for vaporizing the liquid-phase refrigerant and mixing with the gas-phase refrigerant in the accumulator, the above-mentioned problems are solved. The inventors have found that the above can be solved and have completed the present invention.

That is, the present invention comprises a condenser for condensing and liquefying a refrigerant, a capillary tube, an evaporator for evaporating a liquefied refrigerant, an accumulator, and a compressor for compressing the evaporated and vaporized refrigerant and discharging it to the condenser. In a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture as a refrigerant compressed by a compressor, a gasification method in which a liquid-phase refrigerant accumulated in a refrigerant reservoir of the accumulator is vaporized and mixed with a gas-phase refrigerant of the accumulator. The present invention relates to a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture, characterized in that a chamber is provided in the accumulator.

[0009]

[Function] A gasification chamber for vaporizing the liquid-phase refrigerant accumulated in the refrigerant pool of the accumulator to mix with the vapor-phase refrigerant of the accumulator is provided, and both are mixed in the gasification chamber. The composition of the refrigerant mixture sucked into is uniform. In the present invention, the refrigerating machine oil is not particularly limited. Mineral oil-based lubricating oil, alkylbenzene-based lubricating oil, ester-based lubricating oil, ether-based lubricating oil, or a mixture thereof can be preferably used.

[0010]

EXAMPLES The contents of the present invention will be described more specifically below with reference to examples, but the present invention is not limited to these contents. FIG. 1 is an enlarged sectional explanatory view of an accumulator used in the present invention. Inlet 15 of accumulator 6a
The gas-phase refrigerant 9 of the refrigerant entering from the inside enters into the gasification chamber 14 via the conduit 11a connecting the refrigerant reservoir 10a having the bottom 12 and the gasification chamber 14, while the liquid-phase refrigerant 8 flows into the refrigerant reservoir 1
Collect in 0a. A plurality of small holes 13a are provided in the portion where the pipeline 11a contacts the liquid-phase refrigerant 8, and the liquid-phase refrigerant 8 is introduced into the gasification chamber 14 through the small holes 13a. It is gasified in 14 and mixed with the gas-phase refrigerant in the gasification chamber 14 to form a refrigerant mixture having a uniform composition, which is sucked into the compressor (not shown) from the outlet 16. The arrow indicates the flow direction of the refrigerant.

FIG. 2 is an enlarged sectional explanatory view of another accumulator used in the present invention. Inlet 1 of accumulator 6b
The gas-phase refrigerant 9 of the refrigerant entering from 5 is a plurality of pipelines 11 connecting the refrigerant reservoir 10 b having the bottom 12 and the gasification chamber 14.
After entering b into the gasification chamber 14, the liquid-phase refrigerant 8 accumulates in the refrigerant reservoir 10b. A plurality of small holes 13b are provided in the portion where the pipeline 11b contacts the liquid-phase refrigerant 8, and the liquid-phase refrigerant 8 is introduced into the gasification chamber 14 through the small holes 13b. Gasification chamber 14 as well as being gasified in
The refrigerant is mixed with the gas-phase refrigerant therein, and becomes a refrigerant mixture having a uniform composition, which is sucked into the compressor (not shown) from the outlet 16. The arrow indicates the flow direction of the refrigerant.

FIG. 3 shows an enlarged sectional view of another accumulator used in the present invention. Entrance 1 of accumulator 6c
The gas-phase refrigerant 9 of the refrigerant entering from 5 enters the gasification chamber 14 via the conduit 11c connecting the refrigerant reservoir 10c having the bottom 12 and the gasification chamber 14, while the liquid-phase refrigerant 8 is the refrigerant reservoir 10c. Collect in. The bottom 12 is provided with a plurality of small holes 13c, and the liquid-phase refrigerant 8 is introduced into the gasification chamber 14 through the small holes 13c, is gasified in the gasification chamber 14, and is gasified in the gasification chamber 14. It is mixed with the vapor-phase refrigerant in 14 to form a refrigerant mixture having a uniform composition, which is sucked into the compressor (not shown) from the outlet 16. The arrow indicates the flow direction of the refrigerant.

The position, number, size, etc. of the small holes 13a, 13b, 13c are not particularly limited. It is appropriately determined so that the gasified refrigerant is mixed with the gas phase refrigerant in the gasification chamber 14 to obtain a refrigerant mixture having a uniform composition. As an example of the diameter of the small holes 13a, 13b, 13c,
Specifically, it can be about 1 to 2 mm.

A means for heating the gasification chamber 14 may be provided in order to easily gasify the liquid-phase refrigerant 8 that has entered the gasification chamber 14. When the means for heating the gasification chamber 14 is taken, the bottom portion 12 of the refrigerant reservoir may be made of a heat insulating material so that the bottom portion 12 is provided with heat insulating properties.

When the accumulators 6a to 6c having the above-mentioned configuration are used, the refrigerating machine oil entrained in the refrigerant flowing back from the compressor 1 side to the accumulator when the compressor 1 (see FIG. 4) is stopped is gasified in the gasification chamber. 14 (see FIGS. 1 to 3) and does not flow in the direction of the evaporator 5. And the compressor 1
After the stop, when the pressure reaches equilibrium, the refrigerating machine oil is removed from the gasification chamber 1.
Since it returns from 4 to the compressor 1, the refrigerating machine oil can effectively function at the time of restart.

(Example) An accumulator (capacity of about 100 ml) having the structure shown in FIG. 1 was used in a refrigeration circuit,
KLEA60 [R32 as HFC-based non-azeotropic refrigerant mixture
/ R125 / 134a (weight ratio 20/40/40)], and when the refrigerating device is operated to reach a steady state, a state in which about 30% by volume of the refrigerant in the accumulator is stored is Table 1 shows the results of sampling the gas-phase refrigerant mixture from the suction portion of the compressor and examining its composition by gas chromatographic analysis when about 60% by volume of the refrigerant was accumulated.

(Comparative Example) Table 1 also shows the results of a test conducted using an accumulator (capacity of about 100 ml) having a conventional structure shown in FIG. 5 and KLEA60 in the same manner as in the example.

[0018]

[Table 1]

From Table 1, in the case of the embodiment using the accumulator having the structure used in the present invention, the composition of the refrigerant mixture is uniform irrespective of the amount of refrigerant in the accumulator, and is close to the composition of KLEA60 as the charged refrigerant. It can be seen that the composition is obtained. On the other hand, in the case of the comparative example using the accumulator having the conventional structure, the composition of the refrigerant mixture was changed depending on the amount of the refrigerant in the accumulator, and the composition was different from the composition of KLEA60 as the charged refrigerant.

[0020]

INDUSTRIAL APPLICABILITY The refrigerating apparatus using the HFC-based non-azeotropic refrigerant mixture according to the present invention has no risk of depleting the ozone layer, and the non-flammable HFC-based non-azeotropic refrigerant mixture is used in the refrigeration cycle. Since the change in composition of the refrigerant mixture can be reduced, stable operation can be achieved for a long period of time. Refrigerator oil entrained in the refrigerant that flows back from the compressor side to the accumulator when the compressor is stopped is retained in the gasification chamber of the accumulator, and when the pressure reaches equilibrium, the refrigeration oil flows from the gasification chamber to the compressor. Since it returns to, the refrigerating machine oil can effectively function when restarted. The refrigerating apparatus of the present invention is economical because it has a simple structure, and has a large effect as described above and a high industrial utility value.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional explanatory view of an accumulator used in the present invention.

FIG. 2 is an enlarged cross-sectional explanatory view of another accumulator used in the present invention.

FIG. 3 is an enlarged cross-sectional explanatory view of another accumulator used in the present invention.

FIG. 4 is an example of a refrigeration circuit of a typical conventional refrigeration system.

FIG. 5 is an enlarged cross-sectional explanatory view of a conventional accumulator.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Dryer 4 Capillary tube 5 Evaporator 6, 6a, 6b, 6c Accumulator 7 Exit pipeline 8 Liquid phase refrigerant 9 Gas phase refrigerant 10a, 10b, 10c Refrigerant pool 11a, 11b, 11c Pipe path 12 Bottom 13a, 13b, 13c Small hole 14 Gasification chamber 15 Inlet 16 Outlet

Claims (5)

[Claims] 1. A condenser for condensing and liquefying a refrigerant, a capillary tube, an evaporator for evaporating a liquefied refrigerant, an accumulator, a compressor for compressing the evaporated vaporized refrigerant and discharging it to the condenser, and the like. In a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture as the refrigerant to be used,
An HFC, characterized in that a gasification chamber for vaporizing a liquid-phase refrigerant accumulated in a refrigerant reservoir of the accumulator and mixing with the vapor-phase refrigerant of the accumulator is provided in the accumulator.
Refrigeration system using a non-azeotropic refrigerant mixture. 2. A unit for introducing a liquid-phase refrigerant into the gasification chamber at a portion where a pipeline connecting the refrigerant reservoir provided inside the accumulator and the gasification chamber contacts the liquid-phase refrigerant, or 2. The device according to claim 1, wherein two or more small holes are provided.
The refrigeration system described. 3. The refrigerating apparatus according to claim 2, wherein two or more pipe lines connecting the refrigerant reservoir and the gasification chamber are provided. 4. The bottom of the refrigerant pool of the accumulator,
One or two for introducing liquid-phase refrigerant into the gasification chamber
The refrigerating apparatus according to claim 1, wherein at least one small hole is provided. 5. The refrigerating apparatus according to claim 1, wherein the refrigerating machine oil is a mineral oil type lubricating oil, an alkylbenzene type lubricating oil, an ester type lubricating oil, an ether type lubricating oil or a mixture thereof.