JPH11294331A - Rotary compressor and freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a freezing characteristic by providing a motor comprising a compressing element, a rotary element and a stationary element for driving the element in a closed vessel in which oil having a spefified range of viscousness at a specified temperature is stored. SOLUTION: A motor comprises a compression element 2 and a rotary element 3 and a stationary element 4 driving the element 2 built in a closed vessel 1. In the vessel 1, oil 5 having a viscousity of 5-100 cSt at 40 deg.C is stored, and an a hydrocarbon refrigerant 6 is sealed. The cylinder capacity of rotary compressor of such a motor is set to be 8.14 cc, the refrigerant R600a, refrigerating capacity 170 W, theoritical refrigerating performance 198 W and volume efficiency 86%, respectively. Accordingly, the volume efficiency is improved, thereby reducing the cylinder capacity and ensuring a large freezing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrocarbon refrigerant containing no chlorine or fluorine, such as R-600a or R-29.
The present invention relates to a compressor most suitable for a refrigerant mainly containing 0 or the like.

[0002]

2. Description of the Related Art In recent years, due to problems of environmental pollution, particularly destruction of the ozone layer and global warming, use of chlorine-based chlorofluorocarbon has been restricted, CFC12 has also been restricted, and R134a containing no chlorine has been widely used as an alternative refrigerant. Have been.
However, since R134a contains fluorine, it has a disadvantage that its global warming potential is relatively high. In response to this, in Europe, R-600a has already been adopted as a refrigerant mainly containing hydrocarbons containing no chlorine and fluorine.
The compressor employed in the R-600a is disclosed in
A reciprocating compressor corresponding to R134a as shown in Japanese Patent No. 9737 is used as it is.

[0003]

However, R-60
0a has a refrigerating capacity of only about half of R-134a,
To obtain the same performance as 134a, it is necessary to increase the cylinder volume. This inevitably increased the cost of the compressor and increased the size of the compressor.

[0004] The present invention is intended to solve the above-mentioned conventional problems. In the case of using a hydrocarbon-based refrigerant, refrigerating performance is more easily achieved, and it is not necessary to increase the cylinder volume.
An object is to provide an efficient and highly reliable compressor.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method for preparing 5 to 100 cSt at 40.degree.
A rotary compressor that stores an oil having a viscosity of 2 mm and includes a compression element, and a motor that includes a rotor and a stator that drives the compression element.

As a result, the rotary compressor has a better volumetric efficiency than the reciprocating compressor, so that the required refrigerating capacity can be obtained with a smaller cylinder volume.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a rotary compressor containing oil having a viscosity of 5 to 100 cSt at 40.degree. By using it for the cooling system of the refrigerant, the volume efficiency is improved as compared with the reciprocating compressor, so that the refrigerating performance is more easily obtained, and the viscosity at 40 ° C. is 5 to 100 cSt.
Use of the above oil has the effect of improving the sealing performance of the sliding portion of the rotary compressor, thereby further improving the volumetric efficiency, and obtaining greater refrigeration performance.

[0008] The invention according to claim 2 of the present invention is characterized in that, when R600a is used as a hydrocarbon-based refrigerant by using an oil having a viscosity of 40 to 60 cSt at 40 ° C, the oil is dissolved in the oil. Is optimal for rotary compressors, and has the effect of improving the coefficient of performance (COP), which indicates the efficiency of the compressor, in addition to improving the refrigeration performance.

According to the third aspect of the present invention, by providing two cylinders constituting a compression chamber, R600 is obtained.
When a is used, there is an effect that the vibration accompanying the increase in the cylinder volume can be reduced.

The invention according to claim 4 of the present invention is characterized in that, when R290 is used as a hydrocarbon-based refrigerant by using an oil having a viscosity of 22 to 80 cSt at 40 ° C.,
The viscosity when the refrigerant is dissolved in the oil is optimal for rotary compressors, and in addition to improving the refrigerating performance, it can also improve the coefficient of performance (COP), which indicates the efficiency of the compressor. Have.

According to a fifth aspect of the present invention, there is provided a method in which an extreme pressure additive is used in combination with the oil according to the first, second, or third aspect to provide localized metal contact in a boundary lubrication region. When this occurs, the frictional heat accompanying it reacts with the metal surface to form a film, and this reaction product film acts as a kind of solid lubricant. This has the effect of reducing wear between vanes and providing a more reliable compressor.

According to a sixth aspect of the present invention, when the oil and the liquid refrigerant are separated into two layers in the closed container, the bottom surface of the layer mainly composed of the liquid refrigerant forms the oil supply pipe opening and the vane which constitute the compression element. By making it larger than the groove opening, it is possible to prevent the suction of the liquid refrigerant from the oil supply pipe and the vane groove, and it is possible to always supply sufficient oil to the sliding part from the oil-based layer, This has the effect that a more reliable rotary compressor can be obtained.

According to the invention of claim 7 of the present invention, by lowering the pressure in the closed container, the dissolution of the refrigerant into the oil is reduced as compared with a high-pressure rotary compressor.
This has the effect that the amount of refrigerant charged can be further reduced.

The invention described in claim 8 of the present invention has an effect that it is possible to provide a rotary compressor with a small amount of charged refrigerant by setting the space volume to at least 60% or less of the internal volume of the closed container. Have.

According to a ninth aspect of the present invention, at least a condenser, a dryer, and an evaporator are provided, and the first, second, third, fourth, and fifth aspects of the present invention are provided. In the refrigerating apparatus equipped with the rotary compressor according to claim 6, claim 7, claim 8, the oil is easily returned to the compressor by disposing the evaporator above the compressor. This has the effect that a highly reliable refrigeration system can be provided.

[0016]

1 to 10 show an embodiment of the present invention.
This will be described with reference to (Table 1) and (Table 2).

(Embodiment 1) FIG. 1 shows an embodiment using a hydrocarbon-based refrigerant according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a rotary compressor using a naphthenic mineral oil having a viscosity of 5 to 100 cSt at 0 ° C., comprising a compression element 2 in a closed vessel 1, a rotor 3 for driving the compression element 2, and a stator 4; Oil 5 and hydrocarbon-based refrigerant 6 are sealed. Table 1 compares the refrigerating performance of the reciprocating compressor. The oil used was naphthenic mineral oil,
The invention is not limited to this, and other mineral oils or synthetic oils may be used.

[0018]

[Table 1]

According to the results shown in Table 1, the volume efficiency of the rotary compressor is improved by + 21% as compared with the reciprocating compressor, and the cylinder volume can be reduced accordingly. In addition, a cooling device with higher refrigerating performance can be provided with the same cylinder volume.

In this case, it is needless to say that the cylinder capacity can be further reduced by adopting a variable speed operation system having an operation range exceeding the power supply frequency, for example, an inverter system.

(Embodiment 2) FIG. 2 shows a refrigeration of a rotary compressor using R600a, which is a hydrocarbon-based refrigerant according to an embodiment of the present invention, with the viscosity of oil at 40 ° C. as abscissa. The capacity is plotted on the vertical axis, and the oil viscosity at 40 ° C. is 5, 10, 15, 22, 32, 56, 68, 10
It is a plot of refrigeration performance at 0 cSt.

From these results, it can be seen that if the thickness is 15 cSt or less, the sealing performance is deteriorated, the volume efficiency is reduced, and the refrigerating performance is reduced.

Similarly, FIG. 3 is a graph plotting the viscosity of oil at 40 ° C. on the horizontal axis and the coefficient of performance (COP) indicating the efficiency of the compressor on the vertical axis. Is 5,10,15,22,32,56,68,100
It is a plot of the coefficient of performance (COP) of a rotary compressor at cSt.

From these results, it is found that if the temperature is less than 15 cSt, the refrigerating performance is reduced due to the reduced sealing performance,
In the case of St or higher, the input increases due to the increase of the sliding resistance due to the high viscosity, and the coefficient of performance decreases.

From the above results, considering both the refrigerating capacity and the coefficient of performance, the R60 in the range of 15 to 60 cSt
It can be said that the use of 0a is preferable.

(Embodiment 3) FIG. 4 shows a refrigeration of a rotary compressor using R290, which is a hydrocarbon-based refrigerant according to an embodiment of the present invention, with the viscosity of oil at 40.degree. The capacity is plotted on the vertical axis, and the oil viscosity at 40 ° C. is 5, 10, 15, 22, 32, 56, 68, 10
It is a plot of refrigeration performance at 0 cSt.

From this result, it can be seen that if it is 22 cSt or less, the sealing performance is deteriorated, the volume efficiency is reduced, and the refrigerating performance is reduced.

Similarly, FIG. 5 shows the viscosity of the oil at 40 ° C. on the horizontal axis and the coefficient of performance (COP) indicating the efficiency of the compressor on the vertical axis. Is 5,10,15,22,32,56,68,100
It is a plot of the coefficient of performance (COP) of a rotary compressor at cSt.

From these results, it is found that if the temperature is less than 22 cSt, the refrigerating performance is reduced due to a decrease in the sealing performance.
In the case of St or higher, the input increases due to the increase of the sliding resistance due to the high viscosity, and the coefficient of performance decreases.

From the above results, when considering both the refrigerating capacity and the coefficient of performance, R29 in the range of 22 to 80 cSt is R29.
It can be said that the use of 0 is preferable.

(Embodiment 4) (Table 2) shows a rotary compression using a hydrocarbon-based refrigerant according to an embodiment of the present invention as described in claim 2 and using oil having a viscosity of 15 to 60 cSt at 40 ° C. It is the endurance test result of the machine.

[0032]

[Table 2]

From the above results, it is possible to reduce the abrasion of the components constituting the rotary compressor by using the extreme pressure additive together with the oil. Since it can be reduced, a more reliable rotary compressor can be provided.

(Embodiment 5) FIG. 6 shows a rotary compressor according to a sixth embodiment of the present invention, wherein an oil supply pipe opening 7 and a vane groove opening 8 mainly contain oil in a closed container 1. Even if the layer 5 mainly composed of the liquid refrigerant and the layer 9 mainly composed of the liquid refrigerant are separated into two layers, the layer 5 is always disposed below the bottom surface of the layer 9 mainly composed of the liquid refrigerant. Thereby, the suction of the liquid refrigerant from the oil supply pipe opening 7 and the vane groove opening 8 can be prevented, and sufficient oil can always be supplied to the sliding portion from the oil-based layer 5. Thus, a more reliable rotary compressor can be obtained.

(Embodiment 6) FIG. 7 is a cross-sectional view of a rotary compressor according to an embodiment of the present invention, in which two cylinders 10 constituting a compression chamber are provided. At the time of top dead center, the other cylinder is configured to be at bottom dead center. As a result, the torque fluctuation generated when the shaft rotates is reduced, and when the R600a is used, the vibration accompanying the increase in the cylinder volume can be reduced.

(Embodiment 7) FIG. 8 is a sectional view of a rotary compressor according to an embodiment of the present invention, in which the pressure in the closed vessel 1 is low. As a result, compared with the high-pressure rotary compressor, the amount of the refrigerant dissolved into the oil is reduced, so that the amount of the charged refrigerant can be reduced.

(Eighth Embodiment) FIG. 9 is a sectional view of a rotary compressor according to an eighth embodiment of the present invention, in which the space volume 11 with respect to the inner volume of the sealed container 1 is at least 60% or less. Thereby, the amount of the charged refrigerant can be reduced.

(Embodiment 9) FIG. 10 shows an embodiment in which a hydrocarbon-based refrigerant according to an embodiment of the present invention is used and oil
It is the schematic of the cooling system using the rotary compressor using the thing whose viscosity is 22-68 cSt at 0 degreeC, and 12 is Claim 1 or Claim 2, Claim 3, Claim 4, Claim 5, Claim 5, The rotary compressor according to any one of claims 6 and 7,
3 is a condenser, 14 is a dryer (dryer), 15 is an expansion mechanism (capillary), 16 is an evaporator, and the evaporator 16 is provided above the compressor 12.

In the above configuration, the gas sucked from the suction pipe is compressed by the compressor 12 and discharged from the discharge pipe. The discharged gas is condensed and liquefied in the condenser 13, passes through the drier 14, is further decompressed by the expansion mechanism 15, is evaporated and vaporized in the evaporator 16, cools the evaporator 16, and returns to the compressor 12 again. Inhaled and compressed. Oil is contained in the discharge gas discharged from the compressor 12 and passes through the same cycle as the discharge gas. In the evaporator, the temperature of which decreases most in the middle, the oil viscosity increases, and the oil hardly returns. In particular, if the oil has a relatively high viscosity of 32 to 68 cSt at 40 ° C., it is difficult to return. However, by disposing the evaporator 16 above the compressor 12, the oil from the evaporator 16 to the compressor 12 can be reduced. In addition to the gas flow,
The force due to its own weight is applied, and the oil easily returns to the compressor 12, so that a more reliable rotary compressor can be provided, and the reliability of the refrigeration system can be improved.

[0040]

As is evident from the above embodiment, according to the first aspect of the present invention, a hydrocarbon refrigerant is used at 40.degree.
By using a rotary compressor having an oil having a viscosity of 5 to 100 cSt, preferably 22 to 68 cSt,
Since the volume efficiency is improved as compared with the reciprocating compressor, the advantageous effects that the compressor can be downsized and the cost can be reduced are obtained.

According to the second aspect of the present invention, by using an oil having a viscosity of 15 to 60 cSt at a temperature of 40 ° C., the volume efficiency is further improved when R600a is used as a hydrocarbon-based refrigerant, and a greater refrigerating performance is obtained. And the coefficient of performance (COP), which indicates the efficiency of the compressor, can be improved.

According to the third aspect of the present invention, by providing two cylinders constituting a compression chamber, R600
When a is used, the vibration accompanying the increase in the cylinder capacity can be reduced.

According to the fourth aspect of the present invention, when R290 is used as the hydrocarbon-based refrigerant, the volume efficiency is further improved by using oil having a viscosity of 22 to 80 cSt at 40 ° C. And the coefficient of performance (COP), which indicates the efficiency of the compressor, can be improved.

According to the fifth aspect of the present invention, a rotary compressor is constituted by using an extreme pressure additive in combination with the oil according to any one of the first, second and third aspects. The advantageous effect of reducing wear between the roller and the vane and providing a more reliable compressor is obtained.

According to the invention, when the oil and the liquid refrigerant are separated into two layers in the closed container, the bottom surface of the layer mainly composed of the liquid refrigerant has an oil supply pipe opening and a vane groove constituting a compression element. By making the opening or more, the suction of the liquid refrigerant from the oil supply pipe and the vane groove can be prevented, and only the oil can always be supplied to the sliding part, so that a more reliable rotary compressor is provided. Can be obtained.

According to the seventh aspect of the present invention, by lowering the pressure in the closed container, the dissolution of the refrigerant into the oil is reduced as compared with a high-pressure rotary compressor.
The amount of refrigerant charged can be reduced.

According to the eighth aspect of the present invention, the amount of refrigerant can be reduced by setting the space volume to at least 60% of the internal volume of the closed vessel.

According to the ninth aspect of the present invention, at least a condenser, a dryer and an evaporator are provided.
Alternatively, in the refrigeration system equipped with the rotary compressor according to any one of claims 2, 3, 4, 5, 6, and 7, the evaporator is disposed above the compressor. With this arrangement, the oil can be easily returned to the compressor, so that a more reliable rotary compressor can be provided, and the advantageous effect of improving the reliability of the refrigeration system can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotary compressor according to a first embodiment of the present invention described in claim 1;

FIG. 2 shows an R according to a second embodiment of the present invention as set forth in claim 2;
Characteristic diagram showing the relationship between oil viscosity at 40 ° C. and refrigeration capacity of a rotary compressor when using 600a

FIG. 3 shows an R according to a second embodiment of the present invention as set forth in claim 2;
Characteristic diagram showing the relationship between oil viscosity at 40 ° C and coefficient of performance (COP) when using 600a

FIG. 4 is a graph showing R according to the third embodiment of the present invention.
Characteristic diagram showing the relationship between the oil viscosity at 40 ° C. and the refrigerating capacity of the rotary compressor when 290 is used.

FIG. 5 shows an R according to a third embodiment of the present invention described in claim 4.
Characteristic diagram showing the relationship between oil viscosity at 40 ° C and coefficient of performance (COP) when using 290

FIG. 6 is a sectional view of a rotary compressor according to a fifth embodiment of the present invention described in claim 6;

FIG. 7 is a sectional view of a rotary compressor according to a sixth embodiment of the present invention described in claim 3;

FIG. 8 is a sectional view of a rotary compressor according to a seventh embodiment of the present invention described in claim 7;

FIG. 9 is a sectional view of a rotary compressor according to an eighth embodiment of the present invention described in claim 8;

FIG. 10 is a schematic view of a refrigeration apparatus according to a ninth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Compression element 3 Rotor 4 Stator 5 Oil 6 Hydrocarbon-based refrigerant 7 Oil supply pipe opening 8 Vane groove opening 9 Liquid refrigerant layer 10 Cylinder 11 Space volume 12 Rotary compressor 13 Condenser 14 Dryer 15 Expansion mechanism 16 Evaporator

Claims (9)

[Claims] An oil having a viscosity of 5 to 100 cSt at 40 ° C., a compression element and a compression element are driven in a closed vessel using a refrigerant mainly containing a hydrocarbon-based refrigerant containing no chlorine and fluorine. Rotary compressor having a motor consisting of a rotating rotor and a stator. 2. An oil having a viscosity of 15 to 60 cSt at 40 ° C. and a compression element and the compression element are driven in a closed vessel using R-600a which is a hydrocarbon-based refrigerant containing no chlorine and fluorine. A rotary compressor having a motor consisting of a rotor and a stator. 3. The rotary compressor according to claim 2, further comprising two cylinders forming a compression chamber. 4. Use of R-290, a hydrocarbon-based refrigerant containing no chlorine and fluorine, in a closed container at 40 ° C.
A rotary compressor having oil having a viscosity of 2 to 80 cSt, a compression element, and a motor including a rotor and a stator for driving the compression element. 5. The rotary compressor according to claim 1, wherein an extreme pressure additive is contained in the oil. 6. The oil-liquid refrigerant is separated into two layers in the closed container, wherein the bottom surface of the layer mainly composed of the liquid refrigerant is larger than the opening of the oil supply pipe and the opening of the vane groove constituting the compression element. 5
The horizontal rotary compressor according to any one of the above. 7. The rotary compressor according to claim 1, wherein the pressure in the closed vessel is low. 8. The rotary compressor according to claim 1, wherein a space volume with respect to the internal volume of the closed container is at least 60% or less. 9. A rotary compressor according to any one of claims 1 to 8, comprising at least a condenser, a dryer, an expansion mechanism, and an evaporator. A refrigeration unit installed above the machine.