JP2000274844A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently separate a lubricating oil contained in a heating medium and to improve a refrigerating efficiency by arranging an oil separator between a heat exchanger and a pressure reducing unit by using a carbon dioxide as the medium. SOLUTION: A heating medium (CO2) becoming a high temperature and a high pressure as compressed by a compressor 10 is supplied to a first heat exchanger 30, where the medium is cooled, then sent to an oil separator 20, where a lubricating oil in the medium is separated, and supplied to a pressure reducing unit 50 to be pressure reduced. Thereafter, the medium is supplied to a second heat exchanger 40, evaporated to generate cold air, and then returned to the compressor 10. In this case, a compressing element contained in a sealed case of the compressor 10 is driven by a driving element to suck the medium to be compressed. However, since the oil is contained in the case, a part of the oil is accompanied with the medium and discharged out of the refrigerator. Then, the oil is separated by the separator 20, and returned to the compressor 1 by a return tube 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a refrigerating apparatus using carbon dioxide as a heat medium.

[0002]

2. Description of the Related Art Conventionally, refrigeration systems have been used in various technical fields. FIG. 2 is a circuit diagram of such a refrigeration apparatus.

The refrigeration apparatus shown in FIG. 2 includes a compressor 110 for compressing a heat medium and a first heat exchanger 13 for condensing the heat medium.
0, a decompressor 150 for depressurizing the heat medium, a second heat exchanger 140 for evaporating the heat medium, etc., and a heat medium containing chlorine such as R-22 (hereinafter referred to as a specific CFC gas) is used. ing.

[0004] For example, when such a refrigerating apparatus is used for an air conditioner to perform a cooling operation, the compressor 11
The heat medium compressed at 0 is condensed and liquefied by exchanging heat with the outside air in the first heat exchanger 130, and the liquid heat medium is depressurized by the decompressor 150.

[0005] Thereafter, the heat medium is supplied to the second heat exchanger 140, where it is heated and evaporated by exchanging heat with room air. On the contrary, the room air is cooled, and the room is cooled.

The compressor 110 has various configurations such as a reciprocating compressor, a rotary compressor, and a scroll compressor. Each of the compressors 110 has a compression element having a compression chamber therein. The heat medium is compressed by mechanically reducing the size of the compression chamber.

[0007] Therefore, the occurrence of a sliding portion is inevitable, and lubricating oil is used to suppress wear of the sliding portion.

The lubricating oil only needs to lubricate the sliding parts,
In reality, it gets into the compression chamber, and as a result, the lubricating oil is contained in the heat carrier.

When the heat medium contains lubricating oil in this way, the characteristics of the heat medium deteriorate and the refrigeration efficiency of the refrigeration system decreases.

Therefore, an oil separator 120 is provided to remove the lubricating oil contained in the heat medium discharged from the compressor 110.

[0011]

However, there is a problem that the oil separator 120 cannot be used after the first heat exchanger 130 because the heat medium used in the refrigeration system having the above-mentioned structure is a specific fluorocarbon gas. .

That is, in order to separate the lubricating oil contained in the heat medium, it is preferable that the temperature of the heat medium to be separated is low in view of the solid solubility. In this sense, it is desirable to provide the oil separator 120 in a place where the temperature is low and the refrigeration efficiency is not significantly affected.

[0013] The location of the first heat exchanger 130
Between the first heat exchanger 130 and the pressure reducer 150, the specific CFC gas is almost liquefied when the first heat exchanger 130 exchanges heat, and the oil separator 120 is disposed between the first heat exchanger 130 and the pressure reducer 150. It is difficult to arrange and separate the lubricating oil.

From this point of view, the conventional compressor 110
Between the first heat exchanger 130 and the oil separator 120.
Is provided to separate the lubricating oil.

However, since the temperature of the heat medium discharged from the compressor 110 is high, the efficiency of separating lubricating oil cannot be increased, and it is difficult to improve the refrigerating efficiency and the like.

[0016] In addition, there is a demand for a heat medium which does not cause such environmental destruction as the above specified Freon gas causes destruction of the ozone layer and becomes a regulated object.

Accordingly, an object of the present invention is to provide a refrigeration system that uses a safe heat medium that does not destroy the ozone layer, and that improves the refrigeration efficiency by efficiently separating lubricating oil. I do.

[0018]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 comprises a compression element and a drive element in a sealed case, and stores lubricating oil in the sealed case. A compressor for compressing the heat medium while lubricating a sliding portion of the compression element with lubricating oil, a first heat exchanger through which the heat medium compressed by the compressor flows, and a heat medium from the first heat exchanger , A second heat exchanger through which the heat medium flows from the pressure reducer, and a first heat exchanger and a pressure reducer, which are discharged from the first heat exchanger. It has an oil separator for separating the lubricating oil contained in the heat medium, and a return pipe provided to return the lubricating oil separated by the oil separator to the compressor.

The invention according to claim 2 is characterized in that the compressor is a rotary compressor or a reciprocating compressor.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of a refrigeration apparatus using an air conditioner as an example. A compressor 10 such as a rotary compressor or a reciprocating compressor for compressing a heat medium, an oil separator 20 for separating lubricating oil contained in the heat medium, A first heat exchanger 30 that is cooled by heat exchange between the heat medium and the outside air, a decompressor 50 that depressurizes the heat medium, and a second heat exchanger that is heated by heat exchange of the heat medium with room air or the like. 40, one end of the compressor 1
No. 0 has a return pipe 21 and the like that returns the lubricating oil fixed to the sealed case and separated by the oil separator 20 into the sealed case, and carbon dioxide is used as a heat medium.

Although the carbon dioxide is not condensed like the specific chlorofluorocarbon gas even if it is cooled in the first heat exchanger 30, it is dared to cope with the refrigeration system using the specific chlorofluorocarbon gas. 30. Therefore, carbon dioxide does not evaporate even in the second heat exchanger 40.

Of course, irrespective of whether the heat medium is carbon dioxide or a specific chlorofluorocarbon gas, the first heat exchanger 30 and the second heat exchanger 30
The operation in the heat exchanger 40 is the same.

Since carbon dioxide does not contain chlorine like specific fluorocarbons, it does not cause ozone layer destruction and does not cause environmental destruction.

The heat medium which has been compressed by the compressor 10 to have a high temperature and a high pressure is supplied to the first heat exchanger 30, where the heat is exchanged and cooled.

At this time, when the air conditioner is in the cooling operation,
In the first heat exchanger 30, the heat medium exchanges heat with outside air or the like, loses heat, and is cooled. In the heating operation, the heat medium is cooled by exchanging heat with the room air in the first heat exchanger 30, and as a result, the room air is heated and the room is heated.

The heat medium cooled in the first heat exchanger 30 is
The oil is supplied to the pressure reducer 50 via the oil separator 20 to be reduced in pressure, and is supplied to the second heat exchanger 40.

The compressor 10 has a compression element, a drive element, and the like, which are housed in a closed case.

The compression element is provided with a compression chamber, and the space from the compression chamber expands and contracts by the power from the drive element, so that the heat medium is sucked, compressed, and discharged outside the machine.

Lubricating oil is stored in the sealed case to suppress wear of movable parts in the compression chamber, but a part of the lubricating oil is discharged to the outside while being contained in the heat medium. Therefore, this lubricating oil is separated by the oil separator 20, and the separated lubricating oil is returned to the compressor 10 by the return pipe 21.

As described above, since the carbon dioxide does not condense, the temperature of the heat medium discharged from the first heat exchanger 30 drops, but is in a gaseous state.

Therefore, the solid solubility of the lubricating oil is small, so that the heat medium and the lubricating oil can be efficiently separated, and a situation in which the refrigeration efficiency is reduced can be suppressed.

The heat medium from which the lubricating oil has been removed in this way is heated by exchanging heat in the second heat exchanger 40.

At this time, when the air conditioner is in the cooling operation,
The heat medium is heated by exchanging heat with the indoor air in the second heat exchanger 40, and as a result, the indoor air is cooled to perform cooling. In the heating operation, the second heat exchanger 40
Then, the heat medium exchanges heat with outside air or the like to be cooled.

[0034]

As described above, according to the first aspect of the present invention, carbon dioxide is used as the heat medium, and the oil separator is disposed between the first heat exchanger and the pressure reducer. The lubricating oil contained in can be efficiently separated, and the refrigeration efficiency can be improved.

According to the second aspect of the present invention, since the rotary compressor or the reciprocating compressor is used as the compressor, the lubricating oil contained in the heat medium can be efficiently separated with a simple structure, and the refrigeration efficiency can be improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a refrigeration apparatus applied to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a refrigeration apparatus applied to the description of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Compressor 20 Oil separator 21 Return pipe 30 1st heat exchanger 40 2nd heat exchanger 50 Pressure reducer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroshi Nishikawa, 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Takehiro Nishikawa 2--5, Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Kazuya Sato 2-chome 5-5 Keihanhondori, Moriguchi-shi, Osaka (72) Inventor Yasuo Sakamoto 2 Keihanhondori, Moriguchi-shi, Osaka 5-5, Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A compression element and a drive element are provided in a sealed case, and lubricating oil is stored in the sealed case, and a heat medium is compressed while lubricating at least a sliding portion of the compression element with the lubricating oil. Compressor, a first heat exchanger through which the heat medium compressed by the compressor flows, a decompressor that reduces the heat medium from the first heat exchanger, and a first heat exchanger through which the heat medium flows from the decompressor. (2) a heat exchanger; an oil separator disposed between the first heat exchanger and the pressure reducer, for separating lubricating oil contained in the heat medium discharged from the first heat exchanger; And a return pipe provided to return the lubricating oil separated by the oil separator to the compressor. 2. The refrigeration apparatus according to claim 1, wherein said compressor is a rotary compressor or a reciprocating compressor.