JP2008133820A - Rotary compressor, control method thereof, and air conditioner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor and a control method thereof capable of inhibiting temperature rise of a cylinder due to partial load operation and improving partial load efficiency of the compressor, and an air conditioner using the same. <P>SOLUTION: A rotary compressor includes a cylinder to form a first compressing chamber and a second compressing chamber partitioned from each other and including a first vane slot and a second vane slot which are formed in the first compressing chamber and the second compressing chamber, respectively, and a first roller and a second roller to respectively rotate in the first compressing chamber and the second compressing chamber to compress compressing media, the rotary compressor operating in a full load running mode in which a load running is concurrently performed in the first compressing chamber and the second compressing chamber, and in a partial load running mode in which a load running is performed in only the second compressing chamber, and the rotary compressor further includes a first vane which is accommodated movably in and out of the first vane slot, a vane driving part to enable the first vane to contact and be distanced apart from an outer surface of the first roller to perform a load running and a no-load running in the first compressing chamber, and a controller to control the vane driving part to intermittently perform the load running in the first compressing chamber in the partial load running mode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary compressor, a control method thereof, and an air conditioner using the rotary compressor, and more specifically, a rotary compressor that improves the efficiency of a compressor by intermittently performing a load operation during partial load operation. And a control method thereof, and an air conditioner using the same.

  Generally, a cooling device applied to an air conditioner is configured to change the refrigerant compression capacity for the purpose of energy saving while at the same time performing optimum cooling according to the required conditions by changing the cooling capacity. A variable displacement rotary compressor is used.

  A conventional variable displacement rotary compressor is disclosed in Patent Document 1.

  A conventional variable displacement rotary compressor includes a first cylinder in which a first compression space and a second compression space for compressing a medium to be compressed are formed, and a first vane slot and a second vane slot are respectively formed on an inner wall surface; A second cylinder, a first rolling piston and a second rolling piston which are coupled and pivoted in a state of being eccentric to the rotation axis in the compression space of each cylinder, and are in pressure contact with the rolling piston provided in each vane slot, together with the rolling piston A first vane and a second vane for sucking and compressing the refrigerant;

  On the other hand, the conventional variable displacement rotary compressor has a full-load operation in which the medium to be compressed is simultaneously compressed in the first compression space and the second compression space, and a second compression space in which the second compression space is unloaded. The suction pressure relatively lower than the pressure acting on the second compression space is applied to the second vane to perform the partial load operation in which the medium to be compressed is compressed only in the first compression space.

  When the rotary compressor is operated, the inside of the sealed casing is held at a high pressure by the compressed gas discharged through the discharge port, and the compressed gas inside the casing passes through the gas discharge pipe provided at the upper part of the casing. Guided outside.

However, in such a conventional rotary compressor, since the inside of the casing is maintained at a high pressure during the operation of the compressor, the high-pressure gas inside the casing rotates when the partial load operation of the compressor is continued. Since it leaks into the 2nd compression space holding relatively low pressure from between a shaft and the 2nd rolling piston, it flows back through the 2nd inlet of the 2nd cylinder, and the temperature of an accumulator rises as a result. Not only does the efficiency of the compressor decrease, but the temperature of the cylinder rises during partial load operation.
Korean Patent No. 10-06620044 Specification

  Therefore, an object of the present invention is to improve the partial load operation, thereby suppressing the temperature rise of the cylinder due to the partial load operation and increasing the partial load efficiency of the compressor, a control method thereof, and the use thereof Is to provide an air conditioner.

  To achieve the above object, the present invention forms a first compression chamber and a second compression chamber that are partitioned from each other, and a first vane slot and a second compression chamber that are formed in the first compression chamber and the second compression chamber. A cylinder having a vane slot, and a first roller and a second roller that rotate in the first compression chamber and the second compression chamber, respectively, and compress the medium to be compressed; the first compression chamber and the second compression chamber simultaneously A first vane accommodated in a first vane slot in a full-load operation mode in which the load operation is performed and a rotary compressor operable in a partial load operation mode in which only the second compression chamber is loaded; A vane drive unit that contacts or separates the first vane from the outer surface of the first roller, and loads or unloads the first compression chamber; intermittently loads the first compression chamber in the partial load operation mode. Controls drive of vane drive Providing rotary compressor which comprises a control unit for.

  The controller of this embodiment can control the driving of the vane driving unit so that the first vane contacts or separates from the outer surface of the first roller according to a certain period.

  Further, as another embodiment, it further includes a temperature sensing unit that measures the temperature of the compressed medium discharged from the cylinder, and the control unit can control the driving of the vane driving unit based on the signal of the temperature sensing unit. .

  On the other hand, the vane drive unit communicates with the first vane slot, a high-pressure pipe that communicates with the connection pipe and flows a part of the medium to be compressed discharged from the cylinder, and a compression pipe that communicates with the connection pipe. It is preferable to include a low-pressure pipe through which a part of the medium to be compressed flowing into the chamber flows, and a flow path switching valve provided in the connection pipe to selectively communicate the high-pressure pipe and the low-pressure pipe with the connection pipe.

  The control unit controls the flow path switching valve so that the high pressure pipe and the connection pipe communicate with each other in the load operation of the first compression chamber, and the low pressure pipe and the connection pipe communicate with each other in the no load operation of the first compression chamber. It is preferable to control the flow path switching valve.

  An object of the present invention is to provide a rotary compressor configured as described above; a condenser that exchanges heat between the compressed medium compressed from the rotary compressor and outdoor air; and a reduced pressure of the compressed medium condensed from the condenser. An expansion unit; an evaporator that exchanges heat between the compressed medium expanded from the expanded part and room air; and a gas-liquid of the compressed medium evaporated from the evaporator is separated, and the compressed medium in a gaseous state is rotary compressor It is also achieved by an air conditioner characterized in that it includes an accumulator provided.

  According to another aspect of the present invention, the above object has a cylinder forming a first compression chamber and a second compression chamber that are partitioned from each other, and the first compression chamber and the second compression chamber are loaded simultaneously. In the rotary compressor control method that can be operated in the full-load operation mode to be operated and the partial load operation mode in which only the second compression chamber is loaded, a stage in which the second compression chamber is loaded and operated; It is also achieved by a method for controlling a rotary compressor, comprising the step of intermittently loading the first compression chamber in a mode.

  In this one embodiment, in the partial load operation mode, the first compression chamber can be operated in a load according to a certain period.

  In another embodiment, the method further includes a step of measuring the temperature of the refrigerant to be compressed discharged from the cylinder in the partial load operation mode, and if the temperature of the refrigerant to be compressed is equal to or higher than a predetermined temperature, the first compression chamber is provided. Intermittent load operation is possible.

  According to the present invention, by improving the partial load operation, the rotary compressor that suppresses the temperature rise of the cylinder due to the partial load operation and increases the partial load efficiency of the compressor, the control method thereof, and the air conditioning using the rotary compressor A machine is provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  In various embodiments, components having the same configuration are denoted by the same reference numerals and will be described in a typical embodiment, and in other embodiments, only configurations different from those of the embodiment will be described.

  As shown in FIG. 1, the rotary compressor according to one embodiment of the present invention is installed at the inner upper portion of the sealed casing 9 and the inner lower portion of the casing 9 to rotate the electric element 10. A compression element 20 connected to the shaft 11;

  The electric element 10 includes a rotating shaft 11, a cylindrical stator 12 fixed to the inner surface of the casing 9, and a rotor 13 that is rotatably installed inside the stator 12 and has a central portion coupled to the rotating shaft 11. Including. The electric element 10 is supplied with electric power, and drives the compression element 20 connected by the rotating shaft 11 when the rotor 13 rotates.

  The compression element 20 is provided in a cylinder 30 having an upper first compression chamber 31 and a lower second compression chamber 32 that are partitioned from each other, and in the first compression chamber 31 and the second compression chamber 32, respectively. A first compression unit 40 and a second compression unit 50 operated by the shaft 11 are included.

  The cylinder 30 includes an upper first body 33 in which a first compression chamber 31 is formed, a second body 34 in which a second compression chamber 32 is formed and installed below the first body 33, and a first compression chamber. An intermediate plate 35 disposed between the first body 33 and the second body 34 for partitioning the first compression chamber 32 and the second compression chamber 32; an upper opening of the first compression chamber 31; and a lower side of the second compression chamber 32 A first flange 36 and a second flange 37 mounted on the upper portion of the first body 33 and the lower portion of the second body 34 so as to support the rotating shaft 11 at the same time as closing the opening are included. The rotary shaft 11 passes through the centers of the first compression chamber 31 and the second compression chamber 32 and is connected to the compression units 40 and 50 inside the first compression chamber 31 and the second compression chamber 32.

  The first compression unit 40 and the second compression unit 50 include a first eccentric portion 41 and a second eccentric portion 51 provided on the rotation shaft 11 of the first compression chamber 31 and the second compression chamber 32, respectively, and a first compression chamber. The first roller 42 and the second roller 52 that are rotatably coupled to the outer surfaces of the first eccentric portion 41 and the second eccentric portion 51 so as to rotate in contact with the inner wall surfaces of the first compression chamber 32 and the second compression chamber 32, respectively. Including. The first eccentric portion 41 and the second eccentric portion 51 are arranged in directions opposite to each other so as to maintain a balance. Here, the first roller 42 and the second roller 52 are eccentrically rotated inside the first compression chamber 31 and the second compression chamber 32 to compress the medium to be compressed.

  Further, the first compression unit 40 and the second compression unit 50 divide the compression chambers 31 and 32 in a state where the compression chambers 31 and 32 advance and retreat in the radial direction by the rotation of the first roller 42 and the second roller 52. 1 vane 43 and 2nd vane 53 are included. As shown in FIGS. 1 and 2, the first vane 43 and the second vane 53 are formed on the inner wall surfaces of the compression chambers 31 and 32 so as to be concave in the radial direction. By being accommodated in the vane slot 54, the advance and retreat of the first vane 43 and the second vane 53 is guided. The first vane 43 and the second vane 53 are in contact with the outer surfaces of the first roller 42 and the second roller 52, respectively, and divide the first compression chamber 31 and the second compression chamber 32.

  Meanwhile, the first body 33 and the second body 34 accommodate the first vane 43 and the second vane 53, and guide the first vane 43 and the second vane 53 so that they can enter and exit, and A second vane slot 54 is formed.

  The first vane slot 44 has a thickness substantially the same as the thickness of the first vane 43 on the inner wall surface of the first compression chamber 31 and is formed in a concave shape in the radial direction and outward. In addition, the first vane 43 is attached and fixed to the first vane slot 44 in contact with the rear end of the first vane 43 in the radial direction and outside when the first vane 43 is completely retracted. A magnet 47 that prevents the vane 43 from shaking is provided. Here, it is preferable to form the rear end of the first vane 43 into a curved cross-sectional shape, so that the rear end of the first vane 43 can be easily attached to the magnet 47 when the first vane 43 is retracted. Become.

  On the other hand, in the present invention, the first vane 43 is restrained in the retracted state by applying the suction pressure behind the first vane 43, or the discharge pressure is applied behind the first vane 43. The vane drive part 60 which makes 1 vane 43 advance and retreat is included. The vane drive unit 60 restrains the first vane 43 in such a manner or releases the restraint so that compression or idling is performed in the first compression chamber 31, that is, the first compression chamber. The load capacity or the no-load operation is performed at 31, and the compression capacity is made variable. A specific configuration and operation of the vane driving unit 60 will be described later.

  The second vane slot 54 is recessed toward the outside on the inner wall surface of the second compression chamber 32 to guide the second vane 53, and the second vane 53 separates the second compression chamber 32. In this manner, the second vane 53 is formed by a vane spring accommodating portion 57 provided with a vane spring 55 that pressurizes the second roller 52 against the second roller 52.

  On the other hand, the first body 33 and the second body 34 have a suction port 73 connected to suction pipes 71 and 72 so that a low-pressure compressed medium can flow into the first compression chamber 31 and the second compression chamber 32. In addition, discharge ports 75 and 76 are formed through which the high-pressure compressed medium compressed in the compression chambers 31 and 32 is discharged into the casing 9. As a result, when the rotary compressor 8 is driven, the inside of the casing 9 is held at a high pressure by the medium to be compressed discharged through the discharge ports 75 and 76, and the medium to be compressed inside the casing 9 is placed on the upper part of the casing 9. It is guided to the outside through the discharge pipe 77 provided.

  The compressed medium to be sucked passes through an accumulator 78 and is guided to suction ports 73 of the compression chambers 31 and 32 through suction pipes 71 and 72.

  As shown in FIG. 1, the vane driving unit 60 includes a connecting pipe 61 that communicates with the first vane slot 44, and a high-pressure pipe that communicates with the connecting pipe 61 and flows a part of the medium to be compressed discharged from the casing 9. 62, the connecting pipe 61 and the suction pipe 70, the low pressure pipe 63 through which a part of the medium to be compressed flowing into the compression chambers 31 and 32 flows, and the connecting pipe 61, the high pressure pipe 62 or the low pressure pipe. And a flow path switching valve 64 for selectively communicating 63 with the connecting pipe 61.

  The flow path switching valve 64 is an electric three-way valve installed at a point where the connecting pipe 61, the high pressure pipe 62, and the low pressure pipe 63 are connected. The outlet of the connecting pipe 61 is connected to the first flange 36, and a communication oil passage 36 a that connects the connecting pipe 61 and the first vane slot 44 is formed in the first flange 36.

  On the other hand, the rotary compressor 8 according to the present invention includes a control unit 80 that controls driving of the vane driving unit 60 so as to periodically load-load the first compression chamber 31 in the partial load operation mode. As shown in FIG. 5, the control unit 80 controls the driving of the vane driving unit 60 so that the first vane 43 contacts or is separated from the outer surface of the first roller 42 according to a certain period. The control unit 80 opens the flow path switching valve 64 during a predetermined time Ta according to a predetermined period Tb so that the high-pressure pipe 62 and the connection pipe 61 communicate with each other during the partial load operation. A discharge pressure of the medium to be compressed is applied to the rear, and a full load operation is performed in which a 100% compression action is generated in the first compression chamber 31 and the second compression chamber 32. That is, the control unit 80 of the rotary compressor 8 according to the present invention alternately applies the discharge pressure and the suction pressure of the medium to be compressed to the rear of the first vane 43 from the vane driving unit 60 during the partial load operation. By causing the vane 43 to contact or separate from the outer surface of the first roller 42, the first compression chamber 31 is periodically loaded or unloaded.

  And the rotary compressor 8 by this invention comprises the circuit of an air conditioner. That is, the air conditioner includes a rotary compressor 8 according to the present invention, a condenser 3 that exchanges heat between the compressed medium discharged from the compressor 8 and outdoor air, and an expansion that depressurizes the condensed compressed medium. Part 5, an evaporator 7 for exchanging heat between the expanded compressed medium and room air, and an accumulator 78 for separating the vapor-liquid of the evaporated compressed medium and supplying the compressed medium in a gaseous state to the compressor 8 And formed by.

  Hereinafter, the operation process of the rotary compressor 8 according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, when the flow path switching valve 64 is opened so that the high pressure pipe 62 communicates with the connecting pipe 61, the discharge pressure is applied behind the first vane 43. At this time, since the first vane 43 is pushed toward the first compression chamber 31 by the discharge pressure, the first vane 43 contacts the outer surface of the first roller 42, and the first roller 42 rotates eccentrically, The first vane 43 advances and retreats. On the other hand, as shown in FIGS. 3 and 4, when the flow path switching valve 64 is opened so that the low-pressure pipe 63 communicates with the connecting pipe 61, suction pressure is applied behind the first vane 43. At this time, since the first vane 43 is stopped in the retracted state, idling is performed in the first compression chamber 31. When the first vane 43 moves backward and is stopped (restrained), the rear end of the first vane 43 is attached to the magnet 47, so that the swing of the first vane 43 is prevented. That is, even when a pressure change occurs in the first compression chamber 31 due to the operation of the first roller 42 that rotates idly in the first compression chamber 31, the flow of the first vane 43 does not occur and a quiet operation is established. .

  In the present invention, as described above, the compression or idling is performed in the first compression chamber 31 by controlling the restraint of the first vane 43 through the vane driving unit 60, and the compression capacity can be changed through this. it can. That is, when the discharge pressure is applied to the rear of the first vane 43 and the first vane 43 is brought into contact with the outer surface of the first roller 42 and the first vane 43 is advanced and retracted, the first compression chamber 31 and the first vane 43 are moved. Since the compression operation is performed in both the two compression chambers 32, a large volume of compression is performed, and the compressor 8 according to the present invention is operated in the full load operation mode. On the other hand, when the first vane 43 is restrained by applying suction pressure behind the first vane 43, that is, when the first vane 43 is separated from the outer surface of the first roller 42, the first compression chamber 31 Since the idling is performed and the compression operation is performed only in the second compression chamber 32, the compression capacity is reduced, and the compressor 8 according to the present invention is operated in the partial load operation mode.

  In particular, during partial load operation of the compressor 8, the control unit 80 alternately applies the discharge pressure and the suction pressure to the rear of the first vane 43 at a constant cycle, so that the first vane 43 is removed from the first roller 42. The first compression chamber 31 is periodically loaded or unloaded by contacting or separating the surface.

  As a result, the medium to be compressed leaked into the first compression chamber 31 from between the rotating shaft 11 and the first roller 42 during the partial load operation of the compressor 8 does not flow back through the suction port 73, and the first roller Compressed by the operation of the first vane 43 and the first vane 43, and discharged periodically through the discharge port 75. As a result, the rotary compressor 8 according to the embodiment of the present invention, as shown in FIG. 6, the time of the partial load operation elapses during the partial load operation of the compressor 8. Without increasing the temperature, the temperature of the cylinder 30 decreases according to a certain period, thereby suppressing the temperature increase of the accumulator 78 and improving the efficiency of the compressor 8 as well as improving the efficiency of the partial load operation. it can.

  FIG. 7 shows a rotary compressor according to another embodiment of the present invention. Unlike the above-described embodiment, the rotary compressor 8 ′ according to another embodiment of the present invention further includes a temperature sensing unit 83 that measures the temperature of the refrigerant to be compressed discharged from the casing 9, and the control unit 80 has a temperature. The driving of the vane driving unit 60 is controlled based on the signal from the sensing unit 83.

  The control unit 80 of the rotary compressor 8 ′ according to another embodiment of the present invention is configured so that the temperature of the medium to be compressed discharged from the casing 9 during the partial load operation is shifted from the vane driving unit 60 to the rear of the first vane 43. By alternately applying the discharge pressure and the suction pressure of the compression medium and causing the first vane 43 to contact or separate from the outer surface of the first roller 42, the first compression chamber 31 is operated with or without load.

  That is, if the temperature of the refrigerant to be compressed discharged from the casing 9 through the discharge pipe 77 is equal to or higher than a predetermined temperature, the control unit 80 allows the high-pressure pipe 62 and the connection pipe 61 to communicate with each other during the partial load operation. The conversion valve 64 is opened for a predetermined time, the discharge pressure of the medium to be compressed is applied behind the first vane 43, and 100% compression action occurs in the first compression chamber 31 and the second compression chamber 32. Perform full load operation.

  As a result, the temperature of the compressor 8 ′ does not increase during the partial load operation and the temperature of the accumulator 78 decreases, so that not only the efficiency of the compressor 8 ′ increases but also the efficiency of the load operation increases.

  Thus, by intermittently performing the load operation during the partial load operation of the compressor, the temperature rise of the cylinder due to the partial load operation is suppressed, and the partial load efficiency of the compressor is increased.

  On the other hand, in the above-described embodiment, it is described that the first compression chamber is loaded or unloaded according to a certain cycle during the partial load operation of the compressor. It is also possible to perform a load operation or no load operation.

  Further, in the above-described embodiment, the first compression chamber is loaded or unloaded according to a certain period during the partial load operation, or the first compression chamber is changed depending on the temperature of the medium to be compressed discharged from the compressor. It is described that one compression chamber is loaded or unloaded. However, the first compression chamber can be periodically loaded or unloaded during partial load operation, or can be loaded or unloaded depending on the temperature of the medium to be compressed discharged from the compressor.

It is a vertical sectional view showing a state where a compression operation is performed in a first compression chamber of a rotary compressor according to an embodiment of the present invention. It is a horizontal sectional view by the II-II line of FIG. It is a vertical sectional view showing a state where idling is performed in a first compression chamber of a rotary compressor according to an embodiment of the present invention. FIG. 4 is a horizontal sectional view taken along line IV-IV in FIG. 3. It is a control state figure of the rotary compressor by one Embodiment of this invention. It is a temperature change diagram of a cylinder with respect to time at the time of partial load operation of a rotary compressor by one embodiment of the present invention. It is a vertical sectional view showing a state where a compression operation is performed in a first compression chamber of a rotary compressor according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Condenser 5 Expansion part 7 Evaporator 8 Compressor 8 'Compressor 9 Casing 10 Electric element 11 Rotating shaft 12 Stator 13 Rotor 20 Compression element 30 Cylinder 31 1st compression chamber 32 2nd compression chamber 40 1st compression unit 42 1st roller 43 1st vane 44 1st vane slot 50 2nd compression unit 52 2nd roller 53 2nd vane 54 2nd vane slot 60 vane drive part 61 connection pipe 62 high pressure pipe 63 low pressure pipe 64 channel change valve 71 Suction piping 72 Suction piping 77 Discharge piping 78 Accumulator 80 Control unit 83 Temperature sensing unit

Claims (9)

A first compression chamber and a second compression chamber partitioned from each other; a cylinder having a first vane slot and a second vane slot formed in the first compression chamber and the second compression chamber; A first roller and a second roller that rotate in the compression chamber and the second compression chamber to compress the medium to be compressed, respectively, and the first compression chamber and the second compression chamber are all simultaneously operated under load. In a rotary compressor operable in a load operation mode and a partial load operation mode in which only the second compression chamber is operated under load,
A first vane controllably accommodated in the first vane slot;
A vane drive unit that contacts or separates the first vane from the outer surface of the first roller, and performs a load operation or no-load operation of the first compression chamber;
And a control unit that controls driving of the vane driving unit so that the first compression chamber is intermittently loaded in the partial load operation mode.   2. The rotary according to claim 1, wherein the control unit controls driving of the vane driving unit such that the first vane contacts or separates from an outer surface of the first roller according to a predetermined period. Compressor. A temperature sensing unit that measures the temperature of the medium to be compressed discharged from the cylinder;
The rotary compressor according to claim 1, wherein the control unit controls driving of the vane driving unit based on a signal from the temperature sensing unit. The vane drive unit is
A connecting pipe communicating with the first vane slot;
A high-pressure pipe that communicates with the connecting pipe and in which a part of the medium to be compressed discharged from the cylinder flows;
A low-pressure pipe communicating with the connecting pipe and flowing through a part of the medium to be compressed flowing into the compression chambers;
2. The rotary compressor according to claim 1, further comprising a flow path switching valve that is provided in the connection pipe and selectively communicates the high-pressure pipe and the low-pressure pipe with the connection pipe.   The control unit controls the flow path switching valve so that the high-pressure pipe and the connection pipe communicate with each other in the load operation mode of the first compression chamber, and the low pressure in the no-load operation mode of the first compression chamber. The rotary compressor according to claim 4, wherein the flow path switching valve is controlled so that the pipe and the connection pipe communicate with each other. A rotary compressor according to any one of claims 1 to 5;
A condenser for exchanging heat between the compressed medium compressed from the rotary compressor and outdoor air;
An expansion section for depressurizing the medium to be compressed condensed from the condenser;
An evaporator for exchanging heat between the compressed medium expanded from the expansion section and room air;
An air conditioner comprising: an accumulator for separating the gas-liquid of the compressed medium evaporated from the evaporator and providing the compressed medium in a gaseous state to the rotary compressor. A full-load operation mode in which cylinders forming a first compression chamber and a second compression chamber partitioned from each other are provided, and the first compression chamber and the second compression chamber are simultaneously loaded, and the second compression chamber In the control method of the rotary compressor that can be operated in the partial load operation mode in which only the load operation is performed,
Performing a load operation on the second compression chamber;
And a step of intermittently loading the first compression chamber in the partial load operation mode.   The method of controlling a rotary compressor according to claim 7, wherein the first compression chamber is load-operated according to a constant cycle in the partial load operation mode. Measuring the temperature of the compressed refrigerant discharged from the cylinder in the partial load operation mode,
The method for controlling a rotary compressor according to claim 7 or 8, wherein the first compression chamber is intermittently loaded when the temperature of the refrigerant to be compressed is equal to or higher than a predetermined temperature.

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