KR20090095103A - Hermetic compressor - Google Patents

Abstract

An airtight compressor is provided to prevent foaming during driving of a compressor from being severe by excessively mixing isobutane refrigerant and oil and to lower noise of the compressor. An airtight compressor comprises an airtight container(10). Oil is stored in the airtight container. The oil is mixed with a refrigerant inhaled to the internal space of the airtight container and lubricates a compression unit(30) by being supplied to the compression unit. The oil is obtained by mixing mineral oil and ester oil. The oil mixes the mineral oil and ester oil in the predetermined rate.

Description

Hermetic compressor {HERMETIC COMPRESSOR}

The present invention relates to an oil of a hermetic compressor in which a hydrocarbon-based refrigerant is used.

Refrigerant chlorofluorocarbons (CFCs), which have recently been used in refrigeration equipment and air conditioners, have been found to be the causative agents of destroying the ozone layer in the stratosphere. Such CFCs are R11 (trichloromonofluoromethane), R12 (dichlorodifluoromethane), R113 and the like, and among these, the refrigerant mainly used in the refrigerating device is R12. The R12 is one of the regulated substances known to be the cause of the ozone layer reduction and global greenhouse effect, and research on natural refrigerants as an alternative refrigerant is being actively conducted.

The natural refrigerant is water, ammonia, nitrogen, carbon dioxide, propane, butane, etc., which is not an artificial compound but is naturally present on the earth as a refrigerant. Since it does not adversely affect the global environment, it is actively applied as a refrigerant. Is being reviewed.

Among the natural refrigerants, hydrocarbons include only carbon and hydrogen, and include R50 (meth), R170 (ethane), R290 (propane), R600 (butane), R600a (isobutane), and R1270 (propylene). These hydrocarbons are non-toxic, chemically stable, and exhibit adequate solubility in mineral oils. In addition, the hydrocarbon has an ozone depletion index of 0.0, a global warming index is very low, and the amount of refrigerant injected can be reduced since the specific volume is larger than that of other refrigerants.

In particular, the isobutane (R-600a) is known as an environmentally friendly natural gas that does not destroy the ozone layer and does not affect the greenhouse effect. That is, the isobutane (R600a) is a kind of natural gas that purifies hydrocarbon gas from crude oil refining process with high purity and is a refrigerant having no environmental harmful elements.

However, although the isobutane (R600a) has the advantages described above, due to its chemical and physical properties, the isobutane (R600a) has a disadvantage in that it is difficult to be mutually compatible in the relationship of oil (hereinafter, mixed with refrigeration oil) currently used in a refrigeration system. There is this. Therefore, when isobutane (R600a) is applied to a reciprocating compressor, development of a refrigeration oil suitable for it is required.

As described above, the isobutane is well dissolved with mineral oil, and thus, in the refrigerating apparatus using isobutane, mineral oil is commonly used as a freezer oil.

However, in a refrigerating device using isobutane, such as a reciprocating compressor, since isobutane, which is a refrigerant, dissolves well with mineral oil, which is a refrigerant oil, rather, the foaming occurs severely during startup and operation of the compressor, causing noise. It was.

In addition, as a large amount of oil is discharged together with the refrigerant into the refrigeration cycle, the oil is attached to the inner wall surface of the refrigerant pipe to interfere with the heat exchange between the condenser and the evaporator, thereby lowering the efficiency of the refrigeration cycle.

In addition, there is a problem in that the refrigerant is excessively dissolved in the oil and the viscosity of the oil is lowered, thereby increasing the wear on the lubricating surface.

An object of the present invention, in the reciprocating compressor using isobutane as described above, so that the solubility of the refrigerant and the refrigeration oil is properly maintained to prevent excessive formation of the foaming phenomenon, and the oil is excessive in the refrigeration cycle It is an object of the present invention to provide a hermetic compressor that can prevent the discharge of oil and prevent the viscosity of the oil from lowering.

In order to solve the object of the present invention, the refrigerant is mixed with the refrigerant sucked into the inner space of the sealed container in the refrigerating cycle, and supplied to the compression unit for compressing the refrigerant discharged to the refrigeration cycle, the oil in the sealed container to lubricate the compression unit In the stored hermetic compressor, the oil is provided with a hermetic compressor characterized in that the mixture of mineral oil and ester oil (ester oil).

In the hermetic compressor according to the present invention, when isobutane is used as the refrigerant, the isobutane refrigerant is used by using a mixed oil containing ester oil based on mineral oil so that the affinity with the refrigerant of the isobutane can be appropriately improved. The excessive mixing of oil and oil prevents the formation of the foaming phenomenon in operation of the compressor in advance, thereby reducing the compressor noise. In addition, it is possible to improve the efficiency of the refrigeration cycle by preventing the oil from being excessively leaked into the refrigeration cycle to prevent the heat exchange efficiency is reduced while the oil remains on the refrigerant pipe wall surface of the condenser or evaporator. In addition, when the refrigerant is excessively mixed in the oil, as the viscosity of the oil is diluted, an increase in wear in the compression unit can be prevented in advance, thereby increasing the reliability of the compressor.

Hereinafter, the hermetic compressor according to the present invention will be described in detail based on the embodiment shown in the accompanying drawings.

As shown in FIG. 1, the reciprocating compressor according to the present invention includes a sealed container 10, a drive unit 20 disposed inside the sealed container 10 to generate a reciprocating force, and the drive unit 20. Compression unit 30 that receives the reciprocating force generated in the) and compresses the refrigerant, and the lubrication unit 40 for pumping and supplying oil to each lubrication part of the drive unit 20 and the compression unit 30. It includes.

The hermetically sealed container 10 has a hermetically sealed space 11 formed therein, and one side of the hermetically sealed space 11 has a suction pipe 12 for guiding the refrigerant into the hermetic space 11 from the refrigeration cycle. The discharge pipe 13 is connected to the other side of the sealed space 11 to guide the refrigerant compressed by the compression unit 30 to the refrigeration cycle. In the lower half of the sealed container 10, a predetermined amount of oil 14 is stored to be pumped by the lubrication unit and supplied to the compression unit 30 to lubricate the compression unit 30.

The drive unit 20 includes an outer stator 21 fixed by the support frames 26 and 27 that are elastically supported in the closed space of the sealed container 10, and an inner circumferential surface of the outer stator 21 and a predetermined air gap. an inner stator 22 disposed with an air gap, a winding coil 23 wound around the outer stator 21 and supplied with power from the outside, and between the outer stator 21 and the inner stator 22. It is arranged at regular intervals to the power supply is applied to the winding coil 23, the magnet 24 to be linearly reciprocated and the magnet 24 is coupled to the piston 32 of the compression unit 30 to be described later Consisting of a magnet frame 25. In the outer stator 21 and the inner stator 22, a plurality of sheets of stator sheets are radially assembled or a plurality of blocks are stacked and assembled.

The compression unit 30 is connected to the magnet frame 25, the piston 31 reciprocating in a straight line, the cylinder 31 is slidably inserted and the cylinder 32 to form a predetermined compression space (P) ), A suction valve 33 mounted at the front of the piston 31 to control the suction of the refrigerant while opening and closing the suction flow path 31a formed at the piston 31, and detachable at the front of the cylinder 32. It is composed of a discharge valve 34 which is mounted so as to control the discharge of the refrigerant. 35 is a discharge cover, and 36 is a valve spring.

The lubrication part 40 is a pumping part 41 for pumping the oil 14 filled in a predetermined amount in the lower portion of the hermetic container 10, and the oil pumped by the pumping part 41 and the piston 31 and It consists of an oil path part 42 which supplies to the friction site between the cylinders 32. As shown in FIG.

In the drawings, reference numeral 50 denotes a resonator, 51 and 52 denote a resonant spring, 53 a spring supporter, and RP denotes a loop pipe.

The operation of the reciprocating compressor as described above will be described below.

That is, when power is applied to the winding coil 23, a flux is formed around the winding coil 23, and the flux is a closed loop along the outer stator 21 and the inner stator 22. The magnet 24 is coupled with the magnet frame 25 by the interaction between the flux formed between the outer stator 21 and the inner stator 22 and the flux formed by the magnet 24. In a straight line. In addition, when the direction of the current applied to the winding coil 23 is alternately changed, the flux direction of the winding coil 23 is changed, so that the magnet 24 reciprocates in a straight line. Then, the movement of the magnet 24 is transmitted to the piston 31 of the compression unit 30 by the magnet frame 25 so that the piston 31 is linearly reciprocated in the cylinder 32 while the refrigerant It acts as a compress.

For example, when the piston 31 is retracted, it is supplied to the compression space P through the suction flow path 31a formed in the piston 31. When the piston 31 is advanced, the piston 31 is moved by the suction valve 33. As the suction passage 31a is closed, the refrigerant inside the compression space P is compressed, and the compressed refrigerant is discharged to an external refrigeration cycle through the discharge tube 13. During this compression action, the oil 14 filled in the sealed container 10 is pumped by the operation of the pumping part 41, and the friction part between the piston 31 and the cylinder 32 through the lubrication passage 42. It is supplied to and lubricated.

The refrigerant compressed by the reciprocating compressor of the present invention as described above is environmentally friendly, and a hydrocarbon-based refrigerant is used as a refrigerant having flammability and explosiveness. In other words, the refrigerant is mainly composed of an organic compound refrigerant consisting of only carbon and hydrogen, the hydrocarbon-based refrigerant of the organic compound refrigerant is non-toxic and chemically stable, the ozone layer decay index of 0.0 has a very low global warming index . Such refrigerants include R50 (methane), R170 (ethane), R290 (propane), R600 (butane), R600a (isobutane), R1270 (propylene), and the like. In particular, the isobutane (R600a) is used as a refrigerant compressed by the reciprocating compressor of this embodiment with a molecular formula of CH (CH3) 3.

On the other hand, the oil lubricating the reciprocating compressor (14) is a mixed oil, that is, mineral oil and esters that can satisfy the physical properties and chemical properties with moderate affinity with the isobutane Mixed oils are used in which the oil is mixed in an appropriate proportion. The mineral oil may be classified into paraffin-based and naphtan-based, and in this embodiment, naphtan-based mineral oil is used as well as the paraffin-based.

The mixing ratio of the mineral oil and the ester oil may be about 70%: 30% to 90%: 10%. That is, since the mineral oil is relatively inexpensive compared to the ester oil and has good affinity with the isobutane, it may be preferable to mix the mineral oil so as to occupy a larger amount than the ester oil. If the ester oil is excessively used as the oil 14, the cost of the ester oil is high, and the production cost of the compressor is increased, and the water content rate is higher than that of the mineral oil. As hydrolysis increases, the reliability of the compressor may be degraded. In other words, when the ester oil having a high moisture content is used in the compressor, the ester oil is hydrolyzed at the site of sliding at a high temperature to generate an organic acid, thereby increasing the total acid number of the entire oil. As a result, corrosion or damage in the sliding material of the compressor, the production of copper plating, decrease in viscosity, etc., resulting in increased wear at the friction portion or blockage in the microtubules of the refrigeration cycle as a result of the compressor or It may result in a decrease in reliability of the refrigeration cycle employing this.

Thus, in the case of using a hydrocarbon series, especially isobutane, as a refrigerant of the reciprocating compressor, by using a mixed oil containing ester oil based on mineral oil so that the affinity with the refrigerant of the isobutane can be appropriately improved, Excessive mixing of the isobutane refrigerant and oil prevents the foaming from being severe during the operation of the compressor, thereby lowering the compressor noise. In addition, it is possible to improve the efficiency of the refrigeration cycle by preventing the oil from being excessively leaked into the refrigeration cycle to prevent the heat exchange efficiency is reduced while the oil remains on the refrigerant pipe wall surface of the condenser or evaporator. In addition, when the refrigerant is excessively mixed in the oil, as the viscosity of the oil is diluted, an increase in wear in the compression unit can be prevented in advance, thereby increasing the reliability of the compressor.

In the present embodiment has been described an example in which the mover is applied to a reciprocating compressor in a linear reciprocating motion, the present invention is applied to all compressors using hydrocarbon-based refrigerant as an environmentally friendly refrigerant such as rotary compressor or scroll compressor in addition to the reciprocating compressor. can do.

1 is a longitudinal sectional view showing an example of a reciprocating compressor to which the mixed oil of the present invention is applied.

Claims (6)

In a hermetic compressor in which a refrigerant is mixed with a refrigerant sucked into an inner space of a sealed container in a refrigerating cycle, the oil is stored in the sealed container so as to be supplied to a compression unit for compressing the refrigerant and discharged into the refrigeration cycle, thereby lubricating the compression unit. The oil is hermetic compressor characterized in that the mixture of mineral oil (ester oil) and ester oil (ester oil). The method of claim 1, The oil is a hermetic compressor, characterized in that mixing the mineral oil and ester oil in a ratio of about 70%: 30% to 90%: 10%. The method of claim 1, The refrigerant is a hermetic compressor characterized in that the hydrocarbon (hydrocarbon) series. The method of claim 3, The refrigerant is isobutane (R600a) characterized in that the hermetic compressor. The method according to any one of claims 1 to 4, In the inner space of the sealed container is provided with a drive unit for driving the compression unit, The drive unit is a hermetic compressor including a stator fixed to the inside of the hermetic container and the coil is wound, and a mover having a magnet disposed at a predetermined distance from the stator and reciprocating by interacting with the coil. The method of claim 5, The compression unit mechanically coupled to the mover to reciprocate, a cylinder into which the piston is inserted to form a compression space, a suction valve provided at the front end surface of the piston to limit the intake of the refrigerant; And a discharge valve detachably provided at a front end surface of the cylinder to limit discharge of the refrigerant, and a resonant spring resonating the reciprocating motion of the piston and the mover.

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