WO2011135816A1

WO2011135816A1 - Rotary compressor

Info

Publication number: WO2011135816A1
Application number: PCT/JP2011/002370
Authority: WO
Inventors: 信吾大八木; 裕文吉田; 健苅野; 啓晶中井; 竜一大野; 飯田　登
Original assignee: パナソニック株式会社
Priority date: 2010-04-28
Filing date: 2011-04-22
Publication date: 2011-11-03
Also published as: JPWO2011135816A1; JP5828075B2; CN102859199B; EP2565459A1; EP2565459B1; EP2565459A4; CN102859199A

Abstract

Disclosed is a rotary compressor provided with a compression chamber (39) wherein a single refrigerant of hydrofluoroolefin having double bonds between carbons, or a working refrigerant which at least essentially contains the hydrofluoroolefin mixed with hydrofluorocarbon having no double bonds, is enclosed, and a compression mechanism unit (3) increases the pressure of the working refrigerant; a discharge port (38) for discharging the working refrigerant compressed in the compression chamber; and a discharge muffler (37) which covers the discharge port. The volume of the inner space of the discharge muffler is set in accordance with the density of the working refrigerant. Thus, the pressure loss associated with the increase of the flow rate of the working refrigerant can be reliably reduced, the discharge temperature can be prevented from increasing, and the dissolution of the working refrigerant can be suppressed.

Description

Rotary compressor

The present invention relates to room air conditioners, refrigerators, other air conditioners, etc., which use as a working refrigerant a refrigerant mainly containing hydrofluoroolefins that do not contain chlorine atoms and have a low global warming potential and a double bond between carbons. The present invention relates to a rotary compressor that can be incorporated into a refrigeration cycle.

In conventional refrigeration equipment, the working refrigerant has shifted to HFC (hydrofluorocarbon) system with zero ozone depletion coefficient, but this HFC refrigerant has become a problem in recent years due to its extremely high global warming potential. . Therefore, a refrigerant refrigeration system mainly composed of carbon containing no chlorine atoms and a low global warming potential and a hydrofluoroolefin having a double bond between the carbons has been considered.

By the way, in a refrigeration apparatus or the like, a rotary compressor is used that sucks the working refrigerant evaporated by the evaporator, compresses it to a pressure necessary for condensation, and sends the high-temperature and high-pressure working refrigerant into the refrigerant circuit. Since most of the power of the refrigeration apparatus is used in the compressor, the performance of the compressor greatly affects the performance of the refrigeration apparatus. In order to improve the performance of a rotary compressor used in a conventional HFC-based refrigerant, an optimum shape is designed for using HFC410A, which is a typical working refrigerant.

A rotary compressor is known as one of such rotary compressors (see, for example, Patent Document 1). For example, as shown in FIG. 9, the rotary compressor is one in which an electric motor 101 and a compression mechanism 102 are connected by a shaft 103 and accommodated in a sealed container 100, and the electric motor 101 is constituted by a rotor 104 and a stator 105. A balance weight 106 is provided on the top and bottom of the rotor to reduce vibration and noise in the vertical direction. The rotor 104 is coupled to the compression mechanism unit 102 by a shaft 103, and the compression mechanism is operated by electrically rotating the rotor 104.

The compression mechanism unit 102 is supported by a compression chamber 110 formed by a cylinder 107, an upper end plate 108 and a lower end plate 109 that block both end faces of the cylinder 107, and an upper end plate 108 and a lower end plate 109 in the compression chamber. A roller 111 fitted to the eccentric portion of the shaft 103, and a vane 112 which contacts the outer periphery of the roller 111 and reciprocates following the eccentric rotation of the roller 111 to partition the compression chamber into a low pressure portion and a high pressure portion. ing.

The cylinder 107 is opened with a suction port 114 for sucking the working refrigerant toward the low pressure portion in the compression chamber, and the upper plate 108 discharges the working refrigerant from the high pressure portion formed by turning from the low pressure portion in the compression chamber. A discharge port (not shown) is opened, and the roller 111 is accommodated in a compression chamber 110 formed by a cylinder closed from above and below by an upper end plate 108 and a lower end plate 109. On the upper surface of the discharge port (not shown), there is provided a discharge valve (not shown) that is released when a pressure of a predetermined magnitude or more is applied. A discharge muffler 117 is provided so as to cover the upper surface of the discharge valve.

In the rotary compressor having the above-described configuration, the sliding contact portion of the roller 111 passes through the suction port 114 on the low pressure portion side and gradually separates from the suction chamber, and the working refrigerant is supplied from the suction port 114 to the suction chamber. Inhale. On the other hand, on the high pressure part side, the sliding part of the roller 111 approaches the discharge port (not shown) while gradually reducing the compression chamber 110, and when it is compressed to a predetermined pressure or higher, the discharge valve (not shown). Opens and discharges the working refrigerant from a discharge port (not shown). The discharged working refrigerant is discharged into the sealed space via a space formed by the discharge muffler and the upper end plate.

JP 2008-303887 A

However, in the rotary compressor configured as described above, when a refrigerant mainly containing hydrofluoroolefin not containing chlorine atoms and having a low global warming potential and having a double bond between carbon is used as the working refrigerant, the working refrigerant The suction working refrigerant density is lower than that of HFC410A, which is a typical working refrigerant of conventional HFC refrigerants. For this reason, when using the compressor which used the conventional HFC410A as the working refrigerant, it is necessary to increase the working refrigerant. As a result, the volume of the conventional discharge muffler becomes insufficient as the flow rate increases. Further, since the flow rate is large, if the refrigerant flow is poor, a pressure loss occurs, causing a reduction in the efficiency of the compressor. Further, if the refrigerant stays in the discharge muffler, it causes over-compression, re-expansion, and heat reception of the suction working refrigerant, which causes an excessive rise in the discharged working refrigerant temperature. Refrigerants mainly composed of hydrofluoroolefins that do not contain chlorine atoms and have a double bond between carbon and carbon have the property of easily decomposing at high temperatures. It becomes.

The present invention has been made in view of such problems of the prior art, and provides a rotary compressor that reliably reduces pressure loss, and is highly efficient, reliable, and durable. It is an object.

In order to achieve the above object, in the rotary compressor according to the present invention, the space volume of the discharge muffler is set by the suction working refrigerant density.

This makes it possible to provide a highly efficient rotary compressor that reliably reduces pressure loss and has excellent reliability and durability.

In the rotary compressor according to the present invention, by providing a discharge muffler corresponding to the suction working refrigerant density, even if a working refrigerant having a low global warming potential is used, a decrease in reliability and durability due to refrigerant decomposition is suppressed. In addition, since a proper discharge muffler space area can be ensured, pressure loss can be reliably reduced, so that a highly reliable and highly efficient rotary compressor can be provided.

1 is a longitudinal sectional view of a rotary compressor according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the discharge muffler portion in the first embodiment. FIG. 3 is a longitudinal sectional view of the discharge muffler portion in the first embodiment. FIG. 4 is a graph comparing the refrigerant density sucked by various working refrigerants under the condition that the condensation and saturation temperature is equivalent to R410A in a certain operating range of the compressor. FIG. 5 is a characteristic diagram showing the global warming potential (GWP) according to the mixing ratio of the refrigerant in which two components of tetrafluoropropene and difluoromethane are mixed. FIG. 6 is a longitudinal sectional view of the discharge muffler portion in the second embodiment of the present invention. FIG. 7 is a cross-sectional view of the discharge muffler portion in the third embodiment of the present invention. FIG. 8 is a longitudinal sectional view of a compression mechanism section according to Embodiment 4 of the present invention. FIG. 9 is a longitudinal sectional view of a conventional rotary compressor

The first invention encloses and compresses a single refrigerant containing hydrofluoroolefin having a double bond between carbon and carbon, or a working refrigerant mixed with hydrofluorocarbon which always contains at least a double bond and does not have a double bond. The mechanism portion includes a suction port that sucks the working refrigerant, a compression chamber that uses the working refrigerant sucked from the suction port as a high pressure, a discharge port that discharges the working refrigerant that is high pressure in the compression chamber, A rotary compressor having a discharge muffler covering the discharge port, wherein the volume of the discharge muffler is set according to the density of the working refrigerant, and a pressure loss associated with an increase in the working refrigerant flow rate is ensured. It is possible to provide a rotary compressor that reduces the discharge temperature and prevents an increase in the discharge temperature and suppresses the reduction in reliability and durability due to the decomposition of the working refrigerant.

In the second invention, in particular, the discharge muffler according to the first invention is provided so as to form a space at least above the discharge port, and the working refrigerant is in a state where the flow velocity is high immediately after being discharged from the discharge port. However, since it can avoid colliding with a discharge muffler, a low-noise, low-loss rotary compressor can be provided.

According to a third aspect of the invention, in particular, the discharge muffler according to the first and second aspects of the invention has a shape in which the axial direction of the shaft is a long side, and the discharge muffler is arranged in the flow direction of the working refrigerant discharged from the discharge port. Can reduce the pressure loss and discharge the discharged working refrigerant to a space away from the compression chamber. High efficiency can be achieved.

In the fourth aspect of the invention, in particular, the discharge muffler of the first to third aspects of the invention has a shape in which no space volume is provided around the suction port, and high-temperature working refrigerant does not stay around the suction port. Therefore, the heat reception to the suction working refrigerant can be efficiently reduced, and an excessive increase in the discharge temperature can be prevented. For this reason, since decomposition | disassembly of a working refrigerant | coolant can be reduced, a further highly reliable rotary compressor can be provided.

According to a fifth aspect of the invention, in particular, the discharge muffler of the first to fourth aspects of the invention is provided on the opposite side of the electric motor via the compression portion, and the heat generating portion due to the rotation of the electric motor of the working refrigerant. Therefore, it is easy to secure a space in which a discharge muffler is provided, so that it is possible to provide a rotary compressor that is easy to design and highly reliable. Moreover, since the periphery of the discharge muffler is surrounded by oil, low noise can be realized.

The sixth aspect of the invention is particularly configured to provide a plurality of the discharge mufflers according to the first to fifth aspects of the invention, and even if the space volume of the discharge muffler cannot be secured at one place, it is distributed at a plurality of places. Thus, the degree of freedom in design can be improved, and a small and highly reliable rotary compressor can be provided.

In the seventh invention, in particular, the space volume of the discharge muffler of the first to sixth inventions is increased by 1.01 to 1.7 times compared to the case where the working refrigerant uses R410A. A highly reliable and highly efficient rotary compressor can be provided.

In the eighth invention, in particular, the working refrigerant in the first to seventh inventions, the hydrofluoroolefin is tetrafluoropropene or trifluoropropene, a single refrigerant, or the main component thereof, and the global warming potential is 5 or more. Therefore, it is possible to provide a rotary compressor that has a low environmental load and is highly reliable and highly efficient.

The ninth invention is particularly the working refrigerant of the first to eighth inventions, the hydrofluoroolefin is mainly composed of tetrafluoropropene or trifluoropropene, difluoromethane and pentafluoroethane, and a global warming potential of 5 or more. , 750 or less, each of which is a mixture of two components or three components, has a low environmental load, suppresses the flow rate, and can lower the discharge temperature, effectively and highly reliable and highly efficient. A rotary compressor can be provided.

The tenth invention is particularly set in the eighth or ninth invention such that the global warming potential is 350 or less.

The eleventh aspect of the invention relates to polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, particularly as refrigeration oils used in the working refrigerants of the first to eighth aspects of the invention. Synthetic oils based on oxygenated compounds such as polyol esters and polycarbonates, or synthetic oils based on alkylbenzenes and α-olefins as the main component, effectively rotating with high reliability and efficiency A compressor can be provided.

In the twelfth invention, in particular, the hydrofluoroolefin of the first to eleventh inventions is tetrafluoropropene (HFO1234yf), the hydrofluorocarbon is difluoromethane (HFC32), and the mixing ratio of the mixed refrigerant is tetrafluoropropene (HFO1234yf). The working refrigerant composed of 80% hydrofluorocarbon and 20% difluoromethane (HFC32) is used, and the space volume of the discharge muffler is 1.01 to 1.4 times that of the case where the working refrigerant uses R410A. By enlarging, it is possible to provide a rotary compressor that satisfies GWP 150 or less, has a low environmental load, and is effectively highly reliable and highly efficient.

In the thirteenth invention, in particular, the hydrofluoroolefin of the first to eleventh inventions is tetrafluoropropene (HFO1234yf), the hydrofluorocarbon is difluoromethane (HFC32), and the mixing ratio of the mixed refrigerant is tetrafluoropropene (HFO1234yf). The working refrigerant composed of 60% hydrofluorocarbon and 40% difluoromethane (HFC32) is used, and the space volume of the discharge muffler is 1.01 to 1.2 times larger than the case where the working refrigerant uses R410A. As a result of the expansion, the year-round energy consumption efficiency as an air conditioner can ensure the same performance as HFC410A, and the environmental load can be kept small, effectively providing a highly reliable and highly efficient rotary compressor. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1. FIG. In FIG. 1, a rotary compressor is one in which an electric motor 2 and a compression mechanism 3 are connected by a shaft 31 and housed in a sealed container 1. The compression mechanism 3 includes a cylinder 30 and both ends of the cylinder 30. A compression chamber 39 formed by an upper end plate 34 and a lower end plate 35 that close the surface, and an eccentric portion 31a of the shaft 31 supported by the upper end plate 34 and the lower end plate 35 in the compression chamber 39 are fitted. A roller 32 and a vane 33 that contacts the outer periphery of the roller 32 and reciprocates following the eccentric rotation of the roller 32 to partition the inside of the compression chamber 39 into a low pressure portion and a high pressure portion are provided.

The cylinder 30 is opened with a suction port 40 for sucking the working refrigerant toward the low pressure portion in the compression chamber 39, and the upper end plate 34 is operated from a high pressure portion formed by turning from the low pressure portion in the compression chamber 39. A discharge port 38 for discharging the refrigerant is opened, and the roller 32 is accommodated in a compression chamber 39 formed by the cylinder 30 being closed from above and below by the upper end plate 34 and the lower end plate 35. The discharge port 38 is formed as a hole penetrating the upper end plate 34, and a discharge valve 36 is provided on the upper surface of the discharge port 38 that is released when a pressure of a predetermined magnitude or more is applied. A discharge muffler 37 is provided so as to cover the discharge valve 36.

The operation and action of the rotary compressor configured as described above will be described below. On the low pressure part side, the sliding contact part of the roller 32 passes through the suction port 40 and moves away while gradually expanding the suction chamber. The working refrigerant is sucked into the suction chamber from the suction port 40. On the other hand, on the high pressure side, the sliding portion of the roller 32 approaches the discharge port 38 while gradually reducing the compression chamber 39, and when the pressure is compressed to a predetermined pressure or higher, the discharge valve 36 opens and operates from the discharge port 38. The refrigerant flows out and is discharged from the discharge muffler 37 into the sealed container 1, and passes through the notch 28 formed by the stator 22 and the inner wall of the sealed container 1, and the air gap 26 of the motor 2. It is sent out to the shell 5 space and discharged from the refrigerant discharge pipe 51 to the outside of the sealed container 1. Arrows indicate the refrigerant flow.

Here, in this rotary compressor, a single refrigerant of hydrofluoroolefin having a double bond between carbon and carbon or a mixed refrigerant mixed with a hydrofluorocarbon which always contains at least a double bond is not operated. Used as a refrigerant.

2 is a transverse sectional view of the discharge muffler 37 as seen from the upper end plate 34 in the first embodiment, and FIG. 3 is a longitudinal sectional view of the portion of the discharge muffler 37.

As shown in FIGS. 2 and 3, the space volume of the discharge muffler 37 is a hatched portion covered with the upper end plate 34 and the discharge muffler 37. This space volume is set corresponding to the change in the density of the suction working refrigerant used in the present invention with respect to the density of the working refrigerant used in the compressor as a base.

That is, the suction working refrigerant density used in the base compressor is A, and the suction working refrigerant density used in the present invention is B. When the suction working refrigerant density B is smaller than A, the refrigerant used in the present invention has a flow rate of about A / B times that of the working refrigerant used in the base. For this reason, if the discharge muffler 37 is set to the same spatial volume as the conventional one, the refrigerant flow rate is too high, so that the working refrigerant discharged from the discharge port 38 cannot be allowed within the space volume of the discharge muffler 37. For this reason, the discharge from the discharge muffler 37 to the sealed container space is not smoothly performed and a loss occurs. In addition, backflow to the discharge port 38 is likely to occur, and overcompression and reexpansion are likely to occur. For this reason, the temperature of a refrigerant | coolant rises and decomposition | disassembly at the high temperature which is a subject peculiar to this kind of refrigerant will advance.

From the above, when using the working refrigerant used in the present invention, the space volume of the discharge muffler 37 of the rotary compressor designed for the conventional working refrigerant is set according to the suction working refrigerant density ratio. It has been changed. A specific example of setting the space area of the discharge muffler 37 will be described.

FIG. 4 is a diagram comparing the suction refrigerant density by various working refrigerants under the condition that the condensation and saturation temperature is equivalent to R410A in a certain operating range of the compressor in the first embodiment. The dotted line shown in FIG. 4 is the suction refrigerant density when HFO1234yf and R32 are mixed at a mixing ratio of 5: 5. Even when a refrigerant in which HFO1234yf and R32 are mixed at various ratios, the suction refrigerant density based on the mixing ratio is calculated.

As shown in FIG. 4, when the conventionally used working refrigerant HFC410A is used and when the working refrigerant used in the present invention is HFO1234yf, the suction working refrigerant density ratio under the same conditions is HFO1234yf: HFC410A≈1. : 1.7. For this reason, when HFO1234yf is used as a working refrigerant, a refrigerant having a flow rate approximately 1.7 times that of HFC410A flows.

Therefore, if the discharge muffler 37 is not set larger than the space volume designed when the HFC 410A is used, the space volume is too small and pressure loss occurs. On the other hand, if the space volume is set larger than necessary, the sealed container 1 itself is enlarged, and a compact rotary compressor cannot be designed. For this reason, when the HFO 1234yf is used when the spatial volume of the discharge muffler 37 when using the HFC 410A is used as a base, the spatial volume of the discharge muffler 37 is 1.01 to 1 compared to the case where the HFC 410A is used. It is formed to expand to about .7. Thereby, even when using HFO1234yf, a loss can be reduced, decomposition | disassembly of a refrigerant | coolant can be suppressed, and a compact highly efficient and highly reliable rotary compressor can be provided.

FIG. 5 is a characteristic diagram showing a global warming potential (GWP) according to a mixing ratio of a refrigerant in which two components of tetrafluoropropene and difluoromethane are mixed. When the refrigerant is a single refrigerant of tetrafluoropropene, it becomes GWP4 and shows a very good value. However, since the refrigerating capacity is reduced due to the large specific volume as compared with the refrigerant mixed with hydrofluorocarbon, a larger cooling cycle device is required. In other words, if a refrigerant in which a hydrofluoroolefin having a double bond between carbon and carbon is used as a basic component and a hydrofluorocarbon having no double bond is used, the refrigerant is refrigerated as compared with a single refrigerant of hydrofluoroolefin. It is possible to improve the predetermined characteristics such as capacity and make it easier to use as a refrigerant. Therefore, in the refrigerant to be sealed, the ratio of tetrafluoropropene including a single refrigerant is appropriately selected according to the purpose of the cooling cycle apparatus incorporating the compressor and the above-mentioned conditions such as the GWP restriction. That's fine.

Specifically, as shown in FIG. 5, in order to mix tetrafluoropropene and difluoromethane to make GWP150 or less, difluoromethane is 20 wt% or less, in order to make GWP300 or less, difluoromethane is 40 wt% or less, Will be mixed with. In other words, when the mixing ratio of HFO1234yf and R32 is 8: 2, GWP150 or less can be satisfied, and the ratio of the density of the suction gas at this time is HFO1234yf: HFC410A≈1: 1.4. For this reason, when HFO1234yf and R32 are used as working refrigerants, a refrigerant having a flow rate approximately 1.4 times that of HFC410A flows. Therefore, when the HFO 1234yf is used based on the spatial volume of the discharge muffler 37 when the HFC 410A is used, the spatial volume of the discharge muffler 37 is 1.01 to 1 compared with the case where the HFC 410A is used. If the magnification is increased by about 4 times, the influence on the global environment is suppressed, the loss is reduced, and the decomposition of the refrigerant is suppressed, so that a highly efficient and highly reliable rotary compressor can be provided.

In addition, when HFO1234yf and R32 are used as a mixed refrigerant of HFO1234yf and R32 when the ratio is 6: 4, in view of efficiency including pressure loss as a refrigeration cycle device, performance almost equivalent to conventional year-round energy consumption efficiency And GWP could be suppressed to the lowest level. The ratio of the density of the suction gas at this time is HFO1234yf: HFC410A≈1: 1.2. For this reason, when HFO1234yf and R32 are used as working refrigerants, a refrigerant having a flow rate approximately 1.2 times that of HFC410A flows. Therefore, when the HFO 1234yf is used based on the spatial volume of the discharge muffler 37 when the HFC 410A is used, the spatial volume of the discharge muffler 37 is 1.01 to 1 compared with the case where the HFC 410A is used. If it is enlarged to about twice, it is possible to provide a highly efficient and highly reliable rotary compressor because the environmental load is reduced, the loss is reduced, and the decomposition of the refrigerant is suppressed.

Even if the refrigerant that is not recovered by these is released into the atmosphere, the influence on global warming can be kept to a minimum. In addition, the mixed refrigerant mixed at the above ratio can reduce the temperature difference in spite of the non-azeotropic mixed refrigerant and behaves more like a pseudo-azeotropic mixed refrigerant, improving the cooling performance and cooling performance coefficient (COP) of the refrigeration system. can do.

Further, since the discharge muffler 37 is shaped so as to provide a space at least above the discharge port 38, it is possible to prevent the working refrigerant from colliding with the discharge muffler 37 in a state where the flow velocity immediately after being discharged from the discharge port 38 is high. It is possible to provide a rotary compressor with low noise and low loss.

(Embodiment 2)
FIG. 6 is a longitudinal sectional view of the discharge muffler 37 portion in the second embodiment. The second embodiment is different from the first embodiment in the following points, and is basically the same as the first embodiment in the other points. Only the part is explained. The same applies to each embodiment described below.

As shown in FIG. 6, the discharge muffler 37 b has a space volume along the axial direction of the shaft 31. As shown in FIG. 6, the axial length L of the shaft 31 is longer than the horizontal length W of the shaft 31. Since the space volume of the discharge muffler 37b can be ensured while reducing the heat receiving area from the discharge muffler 37b to the compression chamber 39, over-compression and re-expansion can be prevented, and the rise in discharge temperature can be suppressed. Therefore, the decomposition of the refrigerant can be suppressed, and a highly efficient and highly reliable rotary compressor can be provided.

(Embodiment 3)
FIG. 7 is a cross-sectional view of the discharge muffler portion in the third embodiment. As shown in FIG. 7, the discharge muffler 37 c has a shape that avoids the periphery of the suction port 40. As a result, heat received by the suction working refrigerant through the discharge muffler 37c can be efficiently reduced, an excessive increase in the discharge working refrigerant temperature can be prevented, and highly reliable rotary compression that suppresses decomposition of the working refrigerant. Machine can be provided.

(Embodiment 4)
FIG. 8 is a vertical cross-sectional view of the compression mechanism in the fourth embodiment. As shown in FIG. 8, the discharge muffler 37 d is provided on the side opposite to the electric motor 2 so as to cover the lower end plate 35 of the compression chamber 39. Thereby, the working refrigerant can reduce the heat received from the heat generation part due to the rotation of the electric motor 2, and there is no other part such as the electric motor 2 in the vicinity of the discharge muffler 37d, so that it is easy to secure a space for providing the discharge muffler 37d. It is possible to provide a rotary compressor that is easy to design and highly reliable.

Further, since the discharge muffler 37d is surrounded by oil stored around the lower end plate 35, a low-noise rotary compressor can be provided.

It should be noted that the increase in flow rate is not limited to the discharge muffler 37, and it is desirable to set the volume of the pressure loss generation part according to the density of the working refrigerant in the total pressure loss generation part. Based on this design guideline, a rotary compressor that has been conventionally used can be used with a different working refrigerant by a simple design change.

In the above embodiment, a single refrigerant composed of a refrigerant based on a hydrofluoroolefin having a double bond between carbon and carbon or a mixed refrigerant containing the refrigerant is used as a working refrigerant. A refrigerant mixed with a hydrofluoroolefin having a double bond between them as a base component and a hydrofluorocarbon having no double bond may be used as a working refrigerant.

Alternatively, a mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf or HFO1234ze) and the hydrofluorocarbon is difluoromethane (HFC32) may be used as a working refrigerant.

Also, a mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf) and the hydrofluorocarbon is pentafluoroethane (HFC125) may be used as the working refrigerant.

Also, a three-component mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf) and the hydrofluorocarbon is pentafluoroethane (HFC125) and difluoromethane (HFC32) may be used as the working refrigerant.

In any of the above cases, a mixture of two or three components is preferably used so that the global warming potential is 5 or more and 750 or less, preferably 350 or less.

The refrigerating machine oil used for the working refrigerant includes polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and oxygen-containing compounds of polycarbonates. Or a synthetic oil mainly composed of alkylbenzenes or α-olefins.

In each of the above embodiments, the rotary compressor has been described as an example. However, it is needless to say that a scroll compressor which is one of rotary compressors may be used.

As described above, the rotary compressor according to the present invention uses, as a working refrigerant, a single refrigerant composed of a refrigerant based on carbon or a hydrofluoroolefin having a double bond between carbons or a mixed refrigerant containing the refrigerant. Even in this case, high efficiency and high reliability can be achieved. Thereby, it can apply also to the use of rotary compressors, such as an air conditioner, a heat pump type water heater, a refrigerator-freezer, and a dehumidifier.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric motor 26 Air gap 28 Notch part 3 Compression mechanism part 30 Cylinder 31 Shaft 31a Eccentric part 32 Roller 33 Vane 34 Upper end plate 35 Lower end plate 36

Discharge valve

37, 37b, 37c, 37d Discharge muffler 38 Discharge port 39 Compression chamber 40 Suction port 51 Refrigerant discharge pipe

Claims

A single refrigerant containing hydrofluoroolefin having a double bond between carbon and carbon, or at least a working refrigerant mixed with hydrofluorocarbon not containing a double bond is enclosed, and the compression mechanism section includes the working refrigerant. A suction port for sucking in, a compression chamber in which the working refrigerant sucked from the suction port has a high pressure, a discharge port for discharging the working refrigerant in a high pressure in the compression chamber, and a discharge covering the discharge port A rotary compressor including a muffler, wherein a spatial volume of the discharge muffler is set according to a density of the working refrigerant.
The rotary compressor according to claim 1, wherein the discharge muffler is provided so as to form a space at least above the discharge port.
The rotary compressor according to claim 1 or 2, wherein the discharge muffler has a configuration in which an axial direction of the shaft is a long side.
The rotary compressor according to any one of claims 1 to 3, wherein the discharge muffler has a shape that does not provide a space volume around the suction port.
The rotary compressor according to any one of claims 1 to 4, wherein the discharge muffler is provided on the opposite side of the electric motor via the compressor.
The rotary compressor according to any one of claims 1 to 5, wherein a plurality of the discharge mufflers are provided.
The rotary compression according to any one of claims 1 to 6, wherein a space volume of the discharge muffler is expanded by 1.01 to 1.70 times compared to a case where the working refrigerant uses R410A. Machine.
Hydrofluoroolefin is tetrafluoropropene or trifluoropropene and is a single refrigerant or a mixed refrigerant in which two or three components are mixed so that the main component thereof is a global warming potential of 5 or more and 750 or less. The rotary compressor according to any one of claims 1 to 7, wherein a working refrigerant is used.
Hydrofluoroolefin is a mixed refrigerant in which tetrafluoropropene or trifluoropropene is the main component, and difluoromethane and pentafluoroethane are mixed in two or three components so that the global warming potential is 5 or more and 750 or less. The rotary compressor according to any one of claims 1 to 8, wherein a working refrigerant is used.
The rotary compressor according to claim 8 or 9, wherein the global warming coefficient is set to be 350 or less.
Is it a synthetic oil mainly composed of polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and oxygenates of polycarbonates as refrigeration oils? The rotary compressor according to any one of claims 1 to 8, which is a synthetic oil mainly composed of alkylbenzenes and α-olefins.
The hydrofluoroolefin is tetrafluoropropene (HFO1234yf), the hydrofluorocarbon is difluoromethane (HFC32), the mixing ratio of the mixed refrigerant is 80% tetrafluoropropene (HFO1234yf), and the hydrofluorocarbon is 20% difluoromethane (HFC32). 12. The working refrigerant configured as described above, wherein a space volume of the discharge muffler is expanded 1.01 to 1.4 times compared to a case where the working refrigerant uses R410A. A rotary compressor according to claim 1.
The hydrofluoroolefin is tetrafluoropropene (HFO1234yf), the hydrofluorocarbon is difluoromethane (HFC32), the mixing ratio of the mixed refrigerant is 60% tetrafluoropropene (HFO1234yf), and the hydrofluorocarbon is 40% difluoromethane (HFC32). 12. The working refrigerant configured as described above, wherein a space volume of the discharge muffler is expanded 1.01 to 1.2 times compared to a case where the working refrigerant uses R410A. A rotary compressor according to claim 1.