JP2008286037A - Rotary compressor and heat pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-stage compression rotary compressor capable of reducing a pressure loss by absorbing pressure pulsation, and capable of improving compression efficiency in the compressor by cooling an electric motor by using a part as liquid without completely gasifying an injection refrigerant, with a constitution for introducing the injection refrigerant in a gas injection refrigerating cycle into a sealed vessel having the large delivery space volume filled with an intermediate pressure gas refrigerant. <P>SOLUTION: This rotary compressor is provided so that the electric motor 4 and a rotary compression part 3 are stored inside the sealed vessel 2, and the compression part constitutes a two-stage compression part for delivering a high pressure gas refrigerant, by sucking the intermediate pressure gas refrigerant delivered from a low-stage compression part 31 in a high-stage side compression part 32, and is constituted so that the inside of the sealed vessel is put in an atmosphere of the intermediate pressure gas refrigerant delivered from the low-stage side compression part, and the inside of the sealed vessel is connected to the suction side of the high-stage side compression part, and the injection refrigerant in the gas injection refrigerating cycle is introduced inside the sealed vessel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary compressor having a two-stage compression unit used for a refrigeration cycle of a heat pump system such as an air conditioner, and more specifically, inside a sealed container of an intermediate pressure gas refrigerant atmosphere, The present invention relates to a configuration for introducing an intermediate pressure injection refrigerant.

  The configuration of a conventional rotary compressor having a two-stage compression unit is shown in FIG. 7 (see Patent Document 1). The low-pressure Ps gas refrigerant supplied through the pipe 31 ′ is sucked into the low-pressure compression element 20a ′ from the suction port 25a ′ connected to the pipe 31 ′, and the roller (hereinafter referred to as a piston) 11a ′ is swiveled. By this, it is compressed to the intermediate pressure Pm. After the discharge valve 28a ′ is opened and the gas refrigerant having the intermediate pressure Pm discharged from the discharge port 26a ′ is discharged to the discharge space 33 ′, the pressure of the high pressure compression element 20b ′ passes through the intermediate flow path 30 ′. The suction port 25b 'communicates with the chamber 23b'.

  Next, the gas refrigerant having the intermediate pressure Pm passing through the intermediate flow path 30 ′ and sucked into the high pressure compression element 20b ′ from the suction port 25b ′ is compressed to the high pressure Pd by the eccentric rotation of the piston 11b ′. The The discharge valve 28b ′ opens at high pressure Pd, is discharged from the discharge port 26b ′ to the sealed space 29 ′ that is the internal space of the sealed container 13 ′, passes through the gap of the electric motor 14 ′, and is discharged from the discharge pipe 27 ′. . Further, the injection refrigerant is injected into the intermediate space 32 'in the gas refrigerant having the intermediate pressure Pm through the injection pipe 17'.

  Next, FIG. 8 shows a configuration of a refrigeration cycle having an injection cycle using the compressor 1 ′. The refrigerant gas of high pressure Pd discharged from the compressor 1 ′ is condensed by the condenser 3 ′, then expanded by the first expansion mechanism 4 a ′, and the pressure is reduced to the intermediate pressure Pm. The decompressed refrigerant gas is separated into gas and liquid by the gas-liquid separator 6 '. The separated liquid refrigerant is further depressurized to the low pressure Ps by the second expansion mechanism 4b 'downstream of the gas-liquid separator 6' and then evaporated by the evaporator 16 'to become a gas refrigerant. The low-pressure Ps gas refrigerant is sucked into the low-pressure compression element 20a 'from the suction port 25a', and is compressed to the intermediate pressure Pm by the pivoting motion of the piston 11a 'and discharged to the intermediate space 32'.

  The gas refrigerant in the intermediate space 32 'is mixed with the gas refrigerant having the intermediate pressure Pm guided from the injection pipe 17' in which the gas-liquid separator 6 'and the intermediate flow path 30' are communicated. Thereafter, the gas refrigerant having the intermediate pressure Pm sucked into the high-pressure compression element 20b 'from the suction port 25b' is compressed to the high pressure Pd by the swiveling motion of the piston 11b 'and discharged from the discharge pipe 27'.

In the above conventional example, the internal space pressure of the sealed container 13 ′ is high-pressure gas compressed by the high-pressure compression element 20b ′, and the discharge side of the low-pressure compression element 20a ′ and the suction side of the high-pressure compression element 20b ′ are communicated. Injection directly into the intermediate flow path 30 '.
JP 2006-177595 A

  However, in the above conventional example, the internal space pressure of the sealed container 13 ′ is high-pressure gas compressed by the high-pressure compression element 20b ′, and the discharge side of the low-pressure compression element 20a ′ and the suction side of the high-pressure compression element 20b ′ are communicated. Since the injection is directly performed on the intermediate flow path 30 ', there are the following problems as described in Patent Document 1.

  In the intermediate space 32 ′ of the rotary type two-stage compressor 1 ′, the pressure is gradually lowered after being increased in pressure by the refrigerant discharged from the low pressure compression element 20 a ′ and then sucked in by the high pressure compression element 20 b ′. The pressure pulsation is generated at a period corresponding to the rotation speed of the compressor.

  At the stage where the discharge process of the low pressure compression element 20a ′ is completed, the low pressure compression element 20a ′ and the intermediate space 32 ′ are shut off, and the high pressure compression element 20b ′ is out of phase by 180 degrees. In the process. Since the volume obtained by adding the volume of the high-pressure compression element 20b 'to the intermediate space 32' at this stage is the smallest, the pressure in the intermediate space 32 'at this stage is the highest. As the phase further advances, the suction process of the high-pressure compression element 20b 'proceeds and the volume increases, so that the pressure in the intermediate space 32' decreases as the roller 11b 'rotates. This pressure pulsation also propagates in the injection pipe, and the pressure loss of the injection refrigerant increases.

  Therefore, an object of the present invention is to absorb pressure pulsation and reduce pressure loss by introducing the injection refrigerant in the gas injection refrigeration cycle into a large-capacity sealed container, and further, the injection refrigerant is completely gasified. It is an object of the present invention to provide a two-stage compression rotary compressor that can cool the electric motor and improve the compression efficiency of the compressor by using a part of the liquid.

In order to achieve the above-mentioned object, the present invention has several features described below. That is, an electric motor and a rotary compression unit are housed in a sealed container, and the rotary compression unit sucks the intermediate-pressure gas refrigerant discharged from the low-stage compression unit into the high-stage compression unit. In the rotary compressor that constitutes the two-stage compression section for discharging,
The inside of the sealed container is an intermediate-pressure gas refrigerant discharged from the low-stage compression unit, and connects the inside of the sealed container and the suction side of the high-stage compression unit, and the lower part of the motor inside the sealed container In this space, the injection refrigerant in the gas injection refrigeration cycle is introduced.

  Further, the gas injection refrigeration cycle is characterized in that a refrigerant to be injected into the compressor is partially mixed with a liquid refrigerant mainly including the gas refrigerant.

  According to the present invention, the inside of the sealed container is an intermediate-pressure gas refrigerant discharged from the low-stage compression unit, the inside of the sealed container and the suction side of the high-stage compression unit are connected, and the gas is contained inside the sealed container. By adopting a configuration that introduces an intermediate pressure injection refrigerant in the injection refrigeration cycle, pressure pulsation can be absorbed, pressure loss can be reduced, and the intermediate pressure injection refrigerant injected into the compressor is not completely gasified. By using the liquid as the part, the electric motor can be cooled and the compression efficiency of the compressor can be improved.

  An embodiment of the present invention will be described with reference to a longitudinal sectional view of the two-stage compression rotary compressor of FIG. The rotary compressor 1 includes an electric motor 4 above the inside of a cylindrical sealed container 2 and a compression unit 3 below.

  The hermetic container 2 includes a cylindrical main shell 21 and a dome-shaped top shell 22 and a bottom shell 23 that close the upper and lower portions of the main shell 21. The top shell 22 and the bottom shell 23 are fixed to the main shell 21 by welding. Has been.

  The stator 41 of the electric motor 4 is shrunk to the main shell 21, and the rotor 42 of the motor 4 is shrunk and fixed to the shaft 7 that mechanically connects the motor 4 and the compression unit 3. A lower balancer 43 is attached under the rotor 42 in order to balance the centrifugal force of the entire rotating component.

  The compression unit 3 has a low-stage compression unit 31 on the upper side and a high-stage compression unit 32 on the lower side, and opens the discharge side of the low-stage compression unit 31 to the inside of the sealed container 2. And the suction side of the high-stage compression section 32 are connected by an intermediate connecting pipe 24 outside the hermetic container 2 to form a two-stage compression section.

  Next, the structure of each compression part 31 and 32 is demonstrated using FIG. FIG. 2 is a cross-sectional view of the lower stage compression unit 31 in FIG. The high-stage compression section 32 has the same configuration except that the phase of the piston differs by 180 °.

  Each compression part 31, 32 has cylinders 200 and 400, and cylindrical pistons 220 and 420 accommodated inside cylindrical cylinder bores 200a and 400a formed inside the cylinders 200 and 400, respectively. A refrigerant working space is formed between the inner walls of 200a and 400a and the outer peripheral surfaces of the pistons 220 and 420.

  The cylinders 200 and 400 are provided with cylinder grooves 200b and 400b from the cylinder bores 200a and 400a toward the outer circumferential direction, and plate-like vanes 230 and 430 are provided in the cylinder grooves 200b and 400b.

  Springs 240 and 440 are provided between the vanes 230 and 430 and the inner wall of the sealed container 2, and the tip ends of the vanes 230 and 430 are brought into sliding contact with the outer walls of the pistons 220 and 420 by the biasing force of the springs 240 and 440. The working space is divided into suction chambers V1, V2 and compression chambers C1, C2.

  Next, the whole compressor 1 will be described with reference to FIG. A main frame 100 on the low-stage cylinder 200, an intermediate partition plate 300 between the low-stage cylinder 200 and the high-stage cylinder 400, and a subframe 500 under the high-stage cylinder 400; The upper and lower sides of the two working spaces are closed by the main frame 100, the intermediate partition plate 300, and the sub-frame 500, thereby forming a sealed space.

  A low-stage discharge muffler cover 130 and a high-stage discharge muffler cover 510 are provided above the main frame 100 and under the subframe 500, respectively, and a low-stage discharge muffler chamber M1 for reducing pressure pulsation of discharged refrigerant. In addition, a high-stage discharge muffler chamber M4 is formed.

  The low-stage discharge muffler cover 130, the main frame 100, the low-stage cylinder 200, the intermediate partition plate 300, the high-stage cylinder 400, the subframe 500, and the high-stage discharge muffler cover 510 are integrated with bolts (not shown). Further, the outer periphery of the main frame 100 is fixed to the sealed container 2 by spot welding.

  The main frame 100 and the sub-frame 500 have bearing portions 110 and 510, and the shaft 7 is rotatably supported by fitting the shaft 7 to the bearing portions 110 and 510.

  The shaft 7 has two crankshafts 71 and 72 eccentric in directions different from each other by 180 °. One crankshaft 71 is fitted to the piston 220 of the low-stage compression portion 31 and the other crankshaft 72 is on the high-stage side. The piston 420 of the compression part 32 is fitted.

  As the shaft 7 rotates, the pistons 220 and 420 rotate while slidingly contacting the inner walls of the respective cylinder bores 200a and 400a, and the vanes 230 and 430 reciprocate in accordance with the reciprocating movements. , V2 and the volumes of the compression chambers C1, C2 continuously change. Thereby, the compression unit 3 repeats the suction and compression of the refrigerant.

  The suction chamber V <b> 1 of the low-stage compression unit 31 is connected to the refrigerant suction pipe 63 via a low-stage suction hole 210 provided in the low-stage cylinder 200. The compression chamber C1 of the low-stage compression unit 31 is connected to the inside of the hermetic container 2 via a low-stage discharge hole 120 and a low-stage discharge muffler chamber M1 provided in the main frame 100.

  More specifically, a check valve 140 is provided in the low-stage side discharge hole 120, and the refrigerant suction pipe 63 is connected to the low-stage side suction hole 210 via the low-stage side suction connection pipe 211, and the intermediate communication pipe 24. Is connected to the inside of the sealed container 2 through an intermediate discharge connecting pipe 241.

  The suction chamber V <b> 2 of the high stage side compression unit 32 is connected to the intermediate communication pipe 24 through a high stage side suction hole 410 provided in the high stage side cylinder 400. The compression chamber C2 of the high-stage compression section 32 is a refrigerant discharge pipe for discharging refrigerant to the outside of the hermetic container 2 through a high-stage discharge hole 520 and a high-stage discharge muffler chamber M4 provided in the subframe 500. 25.

  More specifically, the high-stage discharge hole 520 is provided with a check valve 540, the intermediate connection pipe 24 is connected to the high-stage suction hole 410 via the intermediate suction connection pipe 411, and the refrigerant discharge pipe 25 is discharged. It is connected to the outside of the hermetic container 2 through the connection pipe 521.

  On the side surface of the compressor body 1, an accumulator 6 including an independent sealed container 61 is provided. A refrigerant return pipe 62 connected to a heat pump system side (not shown) is provided at the upper part of the accumulator 6, and an L-shaped one end is extended to the upper part inside the accumulator 6 at the lower part of the accumulator 6, and the other end is the compressor main body. 1 has a refrigerant suction pipe 63 connected to the suction chamber V1 of the low-stage compression section 31 from one side surface.

  In addition, an injection pipe 26 for introducing intermediate pressure injection refrigerant in a gas injection refrigeration cycle, which will be described later, is connected to a discharge space M2 of the lower stage compression unit 31 below the electric motor 4 inside the sealed container 2.

  Next, the flow of the refrigerant having the above configuration will be described with reference to FIGS. The refrigerant flowing from the system side into the accumulator 6 through the refrigerant return pipe 62 is separated into a liquid refrigerant at the lower part of the accumulator 6 and a gas refrigerant at the upper part of the accumulator 6.

  As the low-stage piston 220 pivots and the volume of the low-stage suction chamber V1 increases, the gas refrigerant in the accumulator 6 passes through the refrigerant suction pipe 63 and the low-stage suction chamber V1 of the compressor body 1. Inhaled.

  After one rotation, the low-stage suction chamber V1 becomes a position that is blocked from the low-stage suction hole 210, and the refrigerant is compressed by switching to the low-stage compression chamber C1 as it is.

  When the compressed refrigerant reaches the pressure in the low-stage discharge muffler chamber M1, which is outside the check valve 140 provided in the low-stage discharge hole 120, that is, the intermediate pressure, the check valve 140 is opened, It is discharged into the stage side discharge muffler chamber M1.

  After reducing the pressure pulsation that causes noise in the low-stage discharge muffler chamber M1, the refrigerant is discharged into the discharge space M2 of the low-stage compression section 31 below the electric motor 4 inside the sealed container 2.

  On the other hand, the intermediate pressure injection refrigerant sucked from the injection pipe 26 is also introduced into the discharge space M2, and merges with the refrigerant compressed by the low-stage compression unit 31.

  The merged refrigerant is guided to the discharge space M3 above the motor 4 through the core notch (not shown) of the stator 41 of the motor 4 and the gap between the core and the winding, and passes through the intermediate connecting pipe 24 to the higher stage side. It is guided to the suction chamber V2 of the compression unit 32.

  The refrigerant guided to the suction chamber V2 of the high-stage compression section 32 is sucked, compressed, and discharged by the high-stage compression section 32 according to the same principle as that of the low-stage compression section 31, and is discharged in the high-stage discharge muffler chamber M4. After reducing the pressure pulsation, it is discharged to the system side through the discharge pipe 25.

  FIG. 3 is a diagram for explaining a refrigeration cycle that is the basis of the air conditioner according to the first embodiment of the present invention. The air conditioner in Embodiment 1 shown in FIG. 3 employs an injection cycle using an internal heat exchanger as means for increasing the enthalpy of the intermediate pressure injection refrigerant, and uses the injection-compatible two-stage compression rotary compressor in the present invention. It is the comprised heat pump system.

  As shown in FIG. 3, the refrigeration cycle includes a basic cycle in which a compressor 1, a condenser 8, a basic cycle expansion mechanism 10, and an evaporator 9 are sequentially connected by a pipe 12.

  Since the operation in this basic cycle is the same as that of a general air conditioner refrigeration cycle, the operation of gas injection relating to the first embodiment will be described below.

  A part of the refrigerant is branched from the basic cycle as an injection refrigerant by the branch pipe 14 after the outlet of the condenser 8 and further depressurized by the injection expansion mechanism 11.

  The decompressed injection refrigerant is heat-exchanged with the refrigerant in the basic cycle after branching by the internal heat exchanger 15. The injection refrigerant whose enthalpy is increased by exchanging heat with the internal heat exchanger 15 is injected into the sealed container 2 of the compressor 1 through the injection pipe 26.

  Here, the compression amount of the compressor is improved by cooling the compressor 1 by controlling the throttle amount of the injection expansion mechanism 11 so that the injection refrigerant is not completely gasified and partially converted into liquid.

  On the other hand, the refrigerant in the basic cycle is reduced in enthalpy by heat exchange in the internal heat exchanger 15, further reduced in pressure by the basic cycle expansion mechanism 10, and then increased in enthalpy in the evaporator 9 and sucked into the compressor 1.

  In the cycle with this gas injection, compared with the cycle without gas injection shown in the first embodiment, the heat radiation capacity is increased in the condenser 8 by increasing the refrigerant circulation flow rate, and the evaporator 9 is in the evaporator. As the enthalpy of the refrigerant at the 9 inlet is reduced, the heat absorption capacity is increased and the capacity as a refrigeration cycle is improved.

  Here, when the evaporator 9 is arranged in the indoor unit, the indoor air is cooled and thus becomes a cooling unit, and when the condenser 10 is arranged in the indoor unit, the indoor air is heated and becomes a heating unit. Although not shown in FIG. 3, if a pipe and a switching valve for replacing the evaporator 9 and the condenser 8 are added to the compressor 1, the internal heat exchanger 15, and the basic cycle expansion mechanism 10, the cooling and heating are performed. It becomes a dual-purpose machine. Further, if the condenser 8 exchanges heat with water for hot water supply, it becomes a hot water heater.

  In the present embodiment, the inside of the sealed container 2 is an intermediate pressure gas refrigerant atmosphere discharged from the low-stage compression section 31, and the inside of the sealed container 2 and the suction side of the high-stage compression section 32 are connected via the intermediate communication pipe 24. Connected. Here, by adopting a configuration in which the intermediate pressure injection refrigerant is introduced into the space below the electric motor 4 inside the sealed container 2, pressure pulsation can be absorbed and pressure loss can be reduced. Further, the intermediate pressure injection refrigerant is not completely gasified but partially converted into liquid, whereby the electric motor 4 can be cooled and the compression efficiency of the compressor 1 can be improved.

  Next, the air conditioner in the second embodiment shown in FIG. 4 employs an injection cycle using an intermediate pressure gas-liquid separator as means for increasing the enthalpy of the intermediate pressure injection refrigerant, and the injection-compatible two-stage compression rotary compression in the present invention. It is the heat pump system comprised using the machine.

  As shown in FIG. 4, the refrigeration cycle basically includes a compressor 1, a condenser 8, a first expansion mechanism 16, an intermediate pressure gas-liquid separator 18, a second expansion mechanism 17, and an evaporator 9 connected in order by a pipe 12. A cycle is configured.

  Since the operation in this basic cycle is the same as that of a general air conditioner refrigeration cycle, the operation of gas injection according to the second embodiment will be described below.

  The refrigerant that has been decompressed to an intermediate pressure by the first expansion mechanism 16 and is in a two-phase state is separated into a gas refrigerant and a liquid refrigerant by an intermediate pressure gas-liquid separator 18, and the gas refrigerant passes through the injection pipe 26 as an injection refrigerant. 1 is injected into the closed container 2.

  Here, the compressor 1 is cooled and the compression efficiency of the compressor is improved by opening a proper amount of the injection liquid flow rate control mechanism 20 and mixing the liquid refrigerant into a part of the injection refrigerant.

  On the other hand, the liquid refrigerant in the intermediate-pressure gas-liquid separator 18 is decompressed by the second expansion mechanism 17 and then sucked into the compressor 1 with an enthalpy increased by the evaporator 9.

  In this gas injection cycle, as in the case of the internal heat exchange type, compared to a cycle in which no gas injection is performed, the condenser 8 increases the heat radiation capacity by increasing the refrigerant circulation flow rate. Decreasing the enthalpy of the refrigerant increases the endothermic capacity and improves the capacity as a refrigeration cycle.

  Here, when the evaporator 9 is arranged in the indoor unit, the indoor air is cooled and thus becomes a cooling unit, and when the condenser 8 is arranged in the indoor unit, the indoor air is heated and becomes a heating unit.

  Although not shown in FIG. 4, if a pipe and a switching valve for exchanging the evaporator 9 and the condenser 8 are added, a cooling / heating dual-purpose machine is obtained. Further, if the condenser 8 exchanges heat with water for hot water supply, it becomes a hot water heater.

  In the present embodiment, the inside of the sealed container 2 is an intermediate pressure gas refrigerant atmosphere discharged from the low-stage compression section 31, and the inside of the sealed container 2 and the suction side of the high-stage compression section 32 are connected via the intermediate communication pipe 24. Connected. Here, by adopting a configuration in which the intermediate pressure injection refrigerant is introduced into the space below the electric motor 4 inside the sealed container 2, pressure pulsation can be absorbed and pressure loss can be reduced. Furthermore, the injection refrigerant is not completely gasified but partially converted into liquid, whereby the electric motor 4 can be cooled and the compression efficiency of the compressor 1 can be improved.

  FIG. 5 shows a longitudinal sectional view of the compressor according to the third embodiment of the present invention. The refrigeration cycle is the same as in Example 1 or 2. As shown in FIG. 5, the discharge space M <b> 2 inside the sealed container 2 and the suction side 410 of the high-stage compression unit 32 are connected to each other through the communication passage 27 inside the sealed container 2. In this way, by adopting a configuration in which the intermediate-pressure gas refrigerant is guided to the suction side 410 of the high-stage compression unit 32 inside the sealed container 2, as shown in FIG. 1, it is provided outside the compressor body 1. The intermediate connecting pipe 24 that has been used is not necessary, and the manufacturing cost can be reduced. Further, in this case, the injection pipe 26 is provided on the upper portion of the electric motor 4 in order to cool the electric motor 4 with the injection refrigerant.

  FIG. 6 shows a longitudinal sectional view of a compressor according to the fourth embodiment of the present invention. In the said Example 1, Example 2, and Example 3, the low stage compression part 31 was arrange | positioned inside the airtight container 2 inside (electric motor 4 side). As shown in FIG. 6, in the third embodiment, the low-stage compression unit 31 is disposed on the lower side (reverse motor 4 side) of the inside of the sealed container 2. With such a configuration, the height of the refrigerant return pipe 62 connected to the accumulator can be reduced, and the packaging height during transportation can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an injection-compatible two-stage compression rotary compressor according to a first embodiment of the present invention. It is a cross-sectional view of the compression part of the injection-compatible two-stage compression rotary compressor according to the first embodiment of the present invention. It is a block diagram of the internal heat exchange type gas injection refrigeration cycle using the injection-compatible two-stage compression rotary compressor of Example 1 in the present invention. It is a block diagram of the intermediate pressure gas-liquid separation type gas injection refrigerating cycle using the injection corresponding | compatible 2 stage | paragraph compression rotary compressor of Example 2 in this invention. It is a longitudinal cross-sectional view of the injection | emission 2 step | paragraph compression rotary compressor of Example 3 in this invention. It is a longitudinal cross-sectional view of the injection corresponding 2 stage | paragraph compression rotary compressor of Example 4 in this invention. It is a longitudinal cross-sectional view of the injection-compatible two-stage compression rotary compressor in the conventional example. It is a block diagram of the refrigerating cycle in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor body 2 Airtight container 3 Compression part 4 Electric motor 6 Accumulator 7 Shaft 8 Condenser (radiator)
9 Evaporator (heat absorber)
DESCRIPTION OF SYMBOLS 10 Basic cycle expansion mechanism 11 Injection expansion mechanism 12 Basic cycle refrigerant piping 13 Injection refrigerant piping 14 Branch pipe 15 Internal heat exchanger 16 First expansion mechanism 17 Second expansion mechanism 18 Intermediate pressure gas-liquid separator 19 Injection gas flow rate Control mechanism 20 Injection liquid flow rate control mechanism 21 Main shell 22 Top shell 23 Bottom shell 24 Intermediate connecting pipe 25 Discharge pipe 26 Injection pipe 27 Connecting passage 31 Low stage compression section 32 High stage compression section 41 Stator 42 Rotor 43 Lower balancer 61 Accumulator container 62 Refrigerant return pipe 63 Refrigerant suction pipe 71 Low-stage crankshaft 72 High-stage crankshaft 100 Main frame 110 Bearing section 120 Low-stage discharge hole 130 Low-stage discharge muffler cover 140 Low-stage check valve 00 Low stage side cylinder 200a Low stage side cylinder bore 200b Low stage side cylinder groove 210 Low stage side suction hole 211 Low stage side suction connection pipe 220 Low stage side piston 230 Low stage side vane 240 Low stage side spring 241 Intermediate discharge connection pipe 300 Partition plate 400 High stage side cylinder 400a High stage side cylinder bore 400b High stage side cylinder groove 410 High stage side suction hole 411 High stage side suction connection pipe 420 High stage side piston 430 High stage side vane 440 High stage side spring 500 Subframe 510 Bearing section 520 High stage side discharge hole 521 High stage side discharge connection pipe 530 High stage side discharge muffler cover 540 High stage side check valve C1 Low stage side compression chamber C2 High stage side compression chamber V1 Low stage side suction chamber V2 High stage Side suction chamber M1 High-stage discharge muffler chamber M2 Low-stage compression section discharge space (under the motor)
M3 Discharge space of the lower stage compression section (on the motor)
M4 High-stage discharge muffler chamber

Claims (2)

An electric motor and a rotary compression unit are housed in a closed container, and the intermediate compression gas refrigerant discharged from the low-stage compression unit is sucked into the high-stage compression unit and discharges the high-pressure gas refrigerant. In the rotary compressor constituting the two-stage compression unit,
The inside of the sealed container is an intermediate-pressure gas refrigerant discharged from the low-stage compression section, connects the inside of the sealed container and the suction side of the high-stage compression section, and gas injection into the sealed container A rotary compressor characterized by introducing an intermediate pressure injection refrigerant in a refrigeration cycle.   The rotary compressor according to claim 1 is used as a compressor, and the intermediate pressure injection refrigerant injected into the compressor is not completely gasified, and has a gas injection refrigeration cycle using a part thereof as a liquid. And heat pump system.

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