JP2018127903A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve COP (coefficient of performance) by securing a flow rate of a refrigerant injected to a compressor.SOLUTION: A compressor 1 includes a low stage side compressor 152A forming a compression chamber between a fixed scroll and a movable scroll, and a high stage side compressor 151A forming a compression chamber between the fixed scroll and the movable scroll. The compressor 1 further includes an intermediate pressure flow passage 142 for guiding a refrigerant delivered from the low stage side compressor 152A to a refrigerant suction port of the high stage side compressor 151A, and an injection flow passage 141 for injecting the intermediate pressure refrigerant flowing from a first expansion valve 3 into the intermediate pressure flow passage 142 and injecting the intermediate pressure refrigerant into the compression chamber of the low stage side compressor 152A.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a compressor.

  Conventionally, in a multi-stage compression cycle, a compressor that houses a high-stage compressor and a low-stage compressor in a case is provided, and a refrigerant discharge port of the high-stage compressor and a refrigerant suction port of the low-stage compressor In this case, a radiator, a first pressure reducing valve, a second pressure reducing valve, a third pressure reducing valve, and an evaporator are connected in series (for example, see Patent Document 1).

  In this configuration, a first refrigerant path for injecting intermediate-stage refrigerant flowing between the refrigerant outlet of the first pressure reducing valve and the refrigerant inlet of the second pressure reducing valve into the working chamber of the high-stage compressor, and a second pressure reducing valve A second refrigerant path for injecting an intermediate stage refrigerant flowing between the refrigerant outlet of the valve and the refrigerant inlet of the third pressure reducing valve into the case;

  The low-stage compressor sucks low-pressure refrigerant from the evaporator, compresses the sucked low-pressure refrigerant, and discharges it into the case. The high stage compressor compresses the refrigerant sucked from the case and the refrigerant sucked from the first refrigerant path and discharges them to the radiator.

JP 2008-144463 A

  In the multistage compression cycle, when the compressor is operated at a low compression ratio, the refrigerant pressure flowing between the refrigerant outlet of the first pressure reducing valve and the refrigerant inlet of the second pressure reducing valve, and the working chamber of the high stage side compressor The differential pressure from the refrigerant pressure is reduced. For this reason, the flow rate of the refrigerant injected into the working chamber of the high-stage compressor through the first refrigerant path is small, and the COP (Coefficient Of Performance) is low.

  In view of the above points, an object of the present invention is to improve the COP by ensuring the refrigerant flow rate injected into the compressor.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a compressor that is applied to a refrigeration cycle (100) for circulating a refrigerant, wherein the compressor (12) is disposed between the fixed portion and the fixed portion (12). And a first movable part (111, 112b) that forms one compression chamber (152), and the displacement of the movable part sucks low-pressure refrigerant into the first compression chamber and compresses and compresses the low-pressure refrigerant in the first compression chamber. A low-stage compressor (152A) to be discharged as a refrigerant;
A fixed portion (12) and a second movable portion (111, 112a) that forms a second compression chamber (151) between the fixed portion and a refrigerant in the second compression chamber by displacement of the second movable portion. A high-stage compressor (151A) that sucks compressed refrigerant through the suction port (127), compresses the compressed refrigerant in the second compression chamber, and discharges the compressed refrigerant as a high-pressure refrigerant;
An intermediate pressure flow path (142) for guiding the compressed refrigerant discharged from the low-stage side compressor to the refrigerant suction port of the high-stage side compressor;
Injecting the intermediate pressure refrigerant generated from the intermediate pressure generating section (3, 5) that constitutes the refrigeration cycle and generates an intermediate pressure refrigerant having an intermediate pressure between the high pressure refrigerant and the low pressure refrigerant into the intermediate pressure flow path; An injection flow path (141) for injecting the intermediate pressure refrigerant into the first compression chamber.

  As described above, the refrigerant pressure of the intermediate pressure refrigerant from the intermediate pressure generator becomes higher than the refrigerant pressure in the first compression chamber. And since the intermediate pressure refrigerant | coolant from an intermediate pressure production | generation part is injected into an intermediate pressure flow path and a 1st compression chamber, the refrigerant | coolant amount of the intermediate pressure refrigerant | coolant injected by a compressor can be ensured. Therefore, the COP of the refrigeration cycle can be improved.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a figure which shows the whole structure of the heat pump cycle in 1st Embodiment of this invention. It is a schematic diagram which shows schematic structure of the compressor of FIG. It is sectional drawing which shows the internal structure of the compressor of FIG. FIG. 4 is a cross-sectional view of the tooth portion of the movable scroll and the tooth portion of the fixed scroll in FIG. 3 cut in a direction perpendicular to the rotation center line of the drive shaft. FIG. 4 is a bottom view of the substrate portion as viewed from below with the lower lid member and the discharge plate removed from the compressor in FIG. 3. It is sectional drawing which shows the internal structure of the non-return valve 60 in FIG. It is sectional drawing which shows the internal structure of the non-return valve 51 in FIG. It is sectional drawing which shows the internal structure of the pressure control valve in 2nd Embodiment of this invention. It is sectional drawing which shows the internal structure of the compressor in 3rd Embodiment of this invention. It is sectional drawing which shows the internal structure of the compressor in 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
The first embodiment will be described below. A heat pump cycle 100 shown in FIG. 1 is used as a part of a heat pump type hot water heater to heat hot water. The heat pump cycle 100 is configured as a gas injection cycle, that is, an economizer-type refrigeration cycle in which an intermediate-pressure gas-phase refrigerant of a cycle is joined to a refrigerant in a pressurizing process in a compression chamber of the compressor 1.

  As shown in FIG. 1, the heat pump cycle 100 includes a compressor 1, a water-refrigerant heat exchanger 2, a first expansion valve 3, a gas-liquid separator 4, a second expansion valve 5, an evaporator 6, and oil separation. A container 7 is provided.

  The compressor 1 is a scroll compressor that sucks and compresses refrigerant from the suction port 30a and discharges the compressed refrigerant to the discharge port 40a. The fluid compressed by the compressor 1, that is, the refrigerant circulating in the heat pump cycle 100, is specifically carbon dioxide (ie, CO2). More specifically, this refrigerant mainly contains carbon dioxide. The refrigerant is mixed with oil that lubricates each sliding portion inside the compressor 1, and part of this oil circulates in the cycle together with the refrigerant.

  The water-refrigerant heat exchanger 2 is a heat exchanger that heats hot water by exchanging heat between hot water for hot water supply and the high-pressure refrigerant discharged from the compressor 1. The first expansion valve 3 decompresses the refrigerant that has flowed out of the water-refrigerant heat exchanger 2.

  The gas-liquid separator 4 is disposed on the downstream side of the refrigerant flow of the first expansion valve 3 and the upstream side of the second expansion valve 5. The intermediate-pressure refrigerant decompressed by the first expansion valve 3 flows into the gas-liquid separator 4. The gas-liquid separator 4 separates the flowing intermediate-pressure refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant. The gas-liquid separator 4 allows a part of the gas-phase refrigerant to flow to the intermediate pressure inflow port 30b of the compressor 1 through the intermediate pressure refrigerant pipe INJ. On the other hand, the gas-liquid separator 4 causes the remaining gas-liquid two-phase refrigerant or the remaining gas-phase refrigerant to flow to the second expansion valve 5.

  The second expansion valve 5 depressurizes the liquid layer refrigerant separated by the gas-liquid separator 4. The evaporator 6 is a heat exchanger that evaporates the refrigerant by exchanging heat between the outside air and the refrigerant decompressed by the second expansion valve 5.

  The oil separator 7 separates the lubricating oil from the high-pressure refrigerant discharged from the compressor 1, and returns the separated lubricating oil to each part in the compressor 1 from the oil return port 41a.

  The first expansion valve 3 and the second expansion valve 5 are electric expansion valves each having an electric motor that adjusts the valve opening degree. The valve opening degree of the first expansion valve 3 and the valve opening degree of the second expansion valve 5 are respectively adjusted by controlling the electric motor in accordance with a control signal from the control device.

  FIG. 2 is a diagram schematically illustrating the internal configuration of the compressor 1. FIG. 3 is a schematic cross-sectional view showing the configuration of the compressor 1. FIG. 3 is not a cross section obtained by cutting a specific surface of the compressor 1, but is configured by collecting a plurality of different cross sections of the compressor 1. Arrow DR1 of FIG. 3 has shown the up-down direction in the state which mounted the compressor 1 in the heat pump type water heater. That is, the double-ended arrow DR1 in FIG. 3 indicates the vertical direction DR1.

  A compressor 1 shown in FIG. 3 is a scroll-type electric compressor, and a compression mechanism unit 10 that compresses refrigerant and an electric motor unit 20 that drives the compression mechanism unit 10 are arranged in the vertical direction (that is, the vertical direction). It is a vertical type. The compressor 1 includes a compression mechanism unit 10, an electric motor unit 20, a housing 30, and the like.

  The heat pump cycle 100 constitutes a supercritical refrigeration cycle in which the pressure of the high-pressure side refrigerant in the cycle from the discharge port 40a of the compressor 1 to the inlet side of the first expansion valve 3 is equal to or higher than the critical pressure.

  In addition to the heat pump cycle 100, the heat pump water heater has a hot water storage tank, a hot water circulation circuit, a water pump, and the like (not shown). The hot water storage tank stores hot water heated by the water-refrigerant heat exchanger 2. The hot water circulation circuit circulates hot water between the hot water storage tank and the water-refrigerant heat exchanger 2. The water pump is disposed in the hot water circulation circuit and pumps hot water.

  The compression mechanism unit 10 sucks, compresses and discharges a refrigerant that is a fluid to be compressed. More specifically, the compression mechanism unit 10 forms a compression chamber, which will be described later, and sucks and compresses low-pressure refrigerant from the suction port 30a into the compression chamber. The compression mechanism unit 10 sucks and compresses the intermediate pressure refrigerant having a pressure higher than that of the low-pressure refrigerant into the compression chamber from the intermediate pressure inflow port 30b. The compression mechanism unit 10 discharges a high-pressure refrigerant obtained as a result of compression of the low-pressure refrigerant and the intermediate-pressure refrigerant in the compression chamber to the discharge port 40a. The electric motor unit 20 drives the compression mechanism unit 10. The housing 30 accommodates the compression mechanism unit 10 and the electric motor unit 20.

  The compressor 1 is a so-called vertical installation in which a drive shaft 25 that transmits rotational driving force from the electric motor unit 20 to the compression mechanism unit 10 extends in the vertical direction DR1, and the compression mechanism unit 10 and the electric motor unit 20 are arranged in the vertical direction. Configured to type. More specifically, in this embodiment, the compression mechanism unit 10 is disposed below the electric motor unit 20.

  The housing 30 includes a cylindrical member 31 whose central axis extends in the vertical direction, a bowl-shaped upper lid member 32 that blocks the upper end of the cylindrical member 31, and a bowl-shaped lower lid member 33 that blocks the lower end of the cylindrical member 31. . The cylindrical member 31, the upper lid member 32, and the lower lid member 33 are integrally joined, so that the housing 30 has a sealed container structure. The cylindrical member 31, the upper lid member 32, and the lower lid member 33 are all made of an iron-based metal, and are joined to each other by welding.

  The housing 30 accommodates the compression mechanism unit 10 and the electric motor unit 20 in the housing 30.

  The electric motor unit 20 includes a stator 21 that forms a stator and a rotor 22 that forms a rotor. The stator 21 is an electric motor having a stator core and a stator coil wound around the stator core.

  Electric power is supplied to the stator coil of the stator 21 through the power supply terminal 23. The power supply terminal 23 is disposed on the upper cover member 32 of the housing 30, that is, the upper end portion of the housing 30. When electric power is supplied to the stator coil, a rotating magnetic field is applied to the rotor 22 to generate a rotational force in the rotor 22, and the drive shaft 25 rotates integrally with the rotor 22.

  The periphery of the motor unit 20 in the housing 30 of the present embodiment communicates with the suction port 30 a through the through hole 29 a of the middle housing 29. For this reason, the circumference | surroundings of the electric motor part 20 among the housings 30 are sealed in the state filled with the low pressure refrigerant | coolant supplied through the suction port 30a.

  The drive shaft 25 is formed in a cylindrical shape, and its internal space is an oil supply passage 251 that supplies lubricating oil to the sliding portion of the drive shaft 25 (that is, a lubrication target portion). The oil supply passage 251 is opened at the lower end surface of the drive shaft 25, and the upper end surface of the drive shaft 25 is closed by the closing member 26.

  A portion of the drive shaft 25 that protrudes below the rotor 22 is provided with a flange 252 that protrudes in the horizontal direction, which is a direction orthogonal to the axial direction parallel to the vertical direction DR1. Is provided with a balance weight 254. Balance weights 221 and 222 are also provided on both sides of the rotor 22 in the vertical direction. The drive shaft 25 is supported by a bearing member 27 and a bearing portion 291 of the middle housing 29.

  The middle housing 29 has a cylindrical shape whose outer diameter and inner diameter increase stepwise from the upper side toward the lower side, and the outermost peripheral surface thereof is fixed to the cylindrical member 31 of the housing 30. An upper portion of the middle housing 29 constitutes a bearing portion 291.

  The movable scroll 11 of the compression mechanism unit 10 is accommodated in a lower part of the middle housing 29. A fixed scroll 12 of the compression mechanism unit 10 is disposed below the movable scroll 11. The fixed scroll 12 is a fixed member that is fixed to the housing 30 and does not rotate. The movable scroll 11 is a turning side member that turns with respect to the fixed scroll 12.

  The movable scroll 11 has a disk-shaped substrate part 111, and the fixed scroll 12 has a substrate part 121. The substrate portions 111 and 121 are arranged so as to face each other in the vertical direction DR1.

  A cylindrical boss portion 113 into which the lower end portion of the drive shaft 25 is inserted is formed at the center portion on the upper surface side of the substrate portion 111 of the movable scroll 11. The lower end portion of the drive shaft 25 is an eccentric portion 253 that is eccentric with respect to the rotation center of the drive shaft 25.

  The movable scroll 11 and the middle housing 29 are provided with anti-rotation mechanisms 11 a and 29 a that prevent the movable scroll 11 from rotating about the eccentric portion 253. Therefore, when the drive shaft 25 rotates, the movable scroll 11 revolves around the rotation center of the drive shaft 25 (that is, turns) without rotating around the eccentric portion 253.

  The movable scroll 11 has tooth portions 112a and 112b protruding from the substrate portion 111 toward the fixed scroll 12 side. The tooth portions 112a and 112b are each formed in a spiral shape. The tooth part 112a is arrange | positioned with respect to the tooth part 112b at the revolution center side.

  On the other hand, the fixed scroll 12 has a tooth part 122 protruding from the substrate part 121 toward the movable scroll 11 side. The tooth portion 122 is formed in a spiral shape and meshes with the tooth portion 112 of the movable scroll 11.

  Then, the teeth 112a and 112b of the movable scroll 11 and the teeth 122 of the fixed scroll 12 are engaged with each other and contacted at a plurality of locations, so that the compression chambers 151 and 152 formed in a crescent shape when viewed from the rotation axis direction. Is formed. These compression chambers 151 and 152 move from the outer periphery toward the revolution center while turning with the turning of the movable scroll 11. And these compression chambers 151 and 152 move, and the volume of these compression chambers 151 and 152 decreases. Due to this volume reduction, the refrigerant in the compression chambers 151 and 152 is compressed.

  At the time shown in FIG. 4, the compression chamber 151 is in a position where the pressure of the refrigerant is highest. The compression chamber 152 is at a position where the refrigerant pressure is an intermediate pressure lower than that of the compression chamber 151.

  The compression chamber 152 constitutes a low-stage compressor 152A. The compression chamber 152 constitutes a high side compressor 152A.

  The fixed scroll 12 corresponds to “a fixed portion that forms the first compression chamber” and “a fixed portion that forms the second compression chamber” in the claims. The substrate portion 111 and the tooth portion 112a of the movable scroll 11 correspond to a “first movable portion” in the claims. The substrate portion 111 and the tooth portion 112b of the movable scroll 11 correspond to a “second movable portion” in the claims.

  As shown in FIGS. 3 and 5, the suction port 30 a, the discharge port 40 a, the intermediate pressure inflow port 30 b, and the oil return port 41 a are fixed to the cylindrical member 31. The suction port 30 a communicates with the compression chamber 152 via the refrigerant flow path 128.

  The intermediate pressure inflow port 30b communicates with the intermediate pressure flow path 142 and the compression chamber 152 (that is, the low-stage compressor 152A) through an injection flow path 141 (see FIG. 5) formed in the substrate portion 121.

  The intermediate pressure channel 142 communicates between the compression chambers 152 and 151 via the discharge holes 126 and 127. That is, the intermediate pressure channel 142 communicates between the low-stage compressor 152A and the high-side compressor 152A via the discharge holes 126 and 127.

  A check valve 51 is disposed between the intermediate pressure inflow port 30 b and the compression chamber 152. The check valve 51 is a valve that stops the refrigerant from flowing backward from the compression chamber 152 to the intermediate pressure inflow port 30b side.

  A check valve 60 is disposed between the injection flow path 141 and the intermediate pressure flow path 142. The check valve 60 is a valve that suppresses the reverse flow of the refrigerant from the intermediate pressure channel 142 to the injection channel 141.

  Each of the injection flow path 141 and the intermediate pressure flow path 142 of the present embodiment is configured by closing the concave portion that opens upward on the upper surface of the discharge plate 14 from above with the substrate portion 121 of the fixed scroll 12. The discharge plate 14 is fixed to the bottom surface of the substrate unit 121.

  FIG. 5 is a bottom view of the substrate unit 121 as viewed from below with the lower lid member 33 and the discharge plate 14 removed from the compressor 1. Small circles 143 and 144 described in FIG. 5 are bolt holes, holes for positioning when the compressor 1 is assembled, sucking holes for lubricating oil, and the like.

  As shown in FIG. 5, a discharge hole 123 through which the refrigerant compressed in the compression chamber 151 is discharged is formed in the center portion of the substrate portion 121 of the fixed scroll 12. A discharge chamber 124 communicating with the discharge hole 123 is formed below the discharge hole 123. As shown in FIG. 5, the substrate portion 121 has an opening 124a that guides the refrigerant from the discharge chamber 124 to the discharge port 40a.

  In the discharge chamber 124, a discharge valve 17 and a stopper 16 that regulates the maximum opening of the discharge valve 17 are arranged. The discharge valve 17 is a reed valve. The discharge valve 17 opens and closes a passage connecting the discharge port 40a and the compression chamber 151. Thereby, the discharge valve 17 allows the refrigerant to flow from the compression chamber 151 to the discharge port 40a in the passage, and suppresses the reverse flow of the refrigerant from the discharge port 40a to the compression chamber 151 in the passage. The passage connecting the discharge port 40a and the compression chamber 151 includes a discharge chamber 124 and a discharge hole 123 described later. One end of the stopper 16 and one end of the discharge valve 17 are fixed to the substrate part 121 by bolts.

  Part of the oil separated by the oil separator 7 is stored inside the oil separator 7, and the other part is stored via the oil return port 41 a, the communication hole 129, and the oil supply passage 251 of the drive shaft 25. It is supplied to the compression mechanism portion 10, the sliding portion between the drive shaft 25 and the bearing member 27, the sliding portion between the drive shaft 25 bearing portion 291 and the like in the housing 30. An oil storage chamber 35 in which lubricating oil is accumulated is formed at the bottom of the housing 30.

  Next, the detailed structure of the check valve 60 and the periphery thereof according to this embodiment will be described with reference to FIG.

  As shown in FIG. 6, the substrate portion 121 of the fixed scroll 12 is provided with an introduction passage 30 </ b> B that guides the refrigerant from the intermediate pressure inflow port 30 b to the intermediate pressure passage 142. A check valve 60 is disposed in the introduction flow path 30B. The check valve 60 includes a free valve 61, a valve seat 62, and a stopper 63.

  The valve seat 62 is formed with a communication hole 62 a that guides the refrigerant from the intermediate pressure inflow port 30 b to the intermediate pressure flow path 142. The stopper 63 is provided with a communication hole 63 a that guides the refrigerant from the communication hole 62 a of the valve seat 62 to the intermediate pressure flow path 142. The free valve 61 is disposed between the valve seat 62 and the stopper 63.

  Here, the free valve 61 is displaced by the differential pressure between the refrigerant pressure from the intermediate pressure inflow port 30 b and the refrigerant pressure in the intermediate pressure flow path 142.

  When the refrigerant pressure in the intermediate pressure channel 142 is greater than the refrigerant pressure in the injection channel 141, the free valve 61 closes the communication hole 62 a of the valve seat 62. For this reason, the check valve 60 can be closed. This stops the refrigerant from the intermediate pressure flow path 142 from flowing toward the intermediate pressure inflow port 30b.

  When the refrigerant pressure in the injection flow path 141 is larger than the refrigerant pressure in the intermediate pressure flow path 142 and the free valve 61 is located at an intermediate position between the valve seat 62 and the stopper 63, The communication hole 62a and the communication hole 63a of the stopper 63 are opened.

  For this reason, the check valve 60 can be opened. As a result, the refrigerant from the intermediate pressure inflow port 30b flows into the intermediate pressure flow path 142 through the communication holes 62a and 63a.

  As described above, the check valve 60 can be opened and closed by the magnitude relationship between the refrigerant pressure in the injection flow path 141 and the refrigerant pressure in the intermediate pressure flow path 142.

  Next, the detailed structure of the check valve 51 and the periphery thereof according to this embodiment will be described with reference to FIG.

  The check valve 51 is disposed in the injection flow channel 141. The check valve 51 includes a fixing member 51 a supported by the substrate part 121.

  A discharge chamber 51d is formed on the downstream side of the refrigerant flow with respect to the fixed member 51a (that is, the compression chamber 152 side) in the injection flow path 141. The discharge chamber 51 d communicates with the compression chamber 152 through the discharge hole 125 formed in the substrate unit 121.

  The fixing member 51a is formed with a discharge hole 51c for introducing the refrigerant flowing from the intermediate pressure inflow port 30b to the discharge hole 125 side through the discharge chamber 51d.

  The discharge valve 51d is made of a steel strip and is disposed in the discharge chamber 51d. The discharge valve 51d is a reed valve that opens and closes the discharge hole 51c by being elastically deformed by the differential pressure between the refrigerant pressure in the discharge chamber 51d and the refrigerant pressure in the discharge hole 125. Thereby, the discharge valve 51d allows the refrigerant to flow from the discharge hole 51c to the discharge chamber 51d and suppresses the reverse flow of the refrigerant from the discharge chamber 51d to the discharge hole 51c.

  Next, the operation of the compressor 1 of this embodiment will be described. First, when electric power is supplied to the motor unit 20 of the compressor 1 and the rotor 22 and the drive shaft 25 rotate, the movable scroll 11 revolves (that is, orbits) with respect to the drive shaft 25. Thereby, the crescent-shaped compression chambers 151 and 152 formed between the tooth portions 112a and 112b of the movable scroll 11 and the tooth portion 122 of the fixed scroll 12 move while turning from the outer peripheral side to the center side.

  First, the low-pressure refrigerant that has flowed out of the evaporator 6 flows into the compression chamber 152 from the suction port 30a through the refrigerant flow path 128. The compression chamber 152 into which the low-pressure refrigerant has flowed moves to a position where it communicates with the discharge hole 126 while reducing its volume as the drive shaft 25 rotates.

  At this time, in a state where the pressure P1 of the intermediate pressure gas phase refrigerant on the intermediate pressure inflow port 30b side is higher than the refrigerant pressure P2 on the compression chamber 152 side, the discharge valve 51d opens the discharge hole 51c of the fixed member 51a.

  Thereby, the intermediate-pressure gas-phase refrigerant from the intermediate-pressure inflow port 30b is injected into the compression chamber 152 through the injection flow path 141, the discharge hole 51c, the discharge chamber 51d, and the discharge hole 125.

  Further, the drive shaft 25 rotates to reach the position of the discharge hole 126 while reducing the volume of the compression chamber 152. Then, the intermediate pressure gas-phase refrigerant compressed by the compression chamber 152 flows into the intermediate pressure channel 142 through the discharge hole 126.

  At this time, the pressure P1 of the intermediate pressure refrigerant on the intermediate pressure inflow port 30b side exceeds the refrigerant pressure P3 of the refrigerant on the intermediate pressure flow path 142 side, and the pressure P1 of the intermediate pressure gas phase refrigerant on the intermediate pressure inflow port 30b side and the intermediate pressure flow path The free valve 61 is positioned at an intermediate position between the valve seat 62 and the stopper 63 due to the pressure difference with the refrigerant pressure P3 of the refrigerant on the 142 side.

  Then, the communication hole 62a of the valve seat 62 and the communication hole 63a of the stopper 63 are opened. Therefore, the intermediate-pressure gas-phase refrigerant from the intermediate-pressure inflow port 30b is injected into the intermediate-pressure channel 142 through the injection channel 141, the communication hole 62a of the valve seat 62, and the communication hole 63a of the stopper 63.

  In this way, the intermediate-pressure gas-phase refrigerant injected into the intermediate-pressure channel 142 flows from the intermediate-pressure channel 142 to the compression chamber 151 through the discharge hole 127.

  Further, the drive shaft 25 rotates to reach the position of the discharge hole 123 while reducing the volume of the compression chamber 151. Then, when the refrigerant pressure of the high-pressure refrigerant compressed by the compression chamber 151 becomes larger than the refrigerant pressure in the discharge chamber 124, the discharge valve 17 opens the discharge hole 123. For this reason, the high-pressure refrigerant flows out from the compression chamber 151 to the water-refrigerant heat exchanger 2 side through the discharge hole 123, the discharge chamber 124, the discharge port 40 a and the oil separator 7.

  In addition, the periphery of the motor unit 20 in the housing 30 is filled with the low-pressure refrigerant supplied from the suction port 30a through the through hole of the middle housing 29.

  According to the present embodiment described above, the compressor 1 applied to the heat pump cycle 10 that circulates the refrigerant includes the fixed scroll 12 and the tooth portion 112b that forms the compression chamber 152 between the fixed scroll 12 and the fixed scroll 12. And a low-stage compressor 152A that sucks low-pressure refrigerant into the compression chamber 152 by the displacement of the tooth portion 112b and compresses and discharges the low-pressure refrigerant in the compression chamber 152.

  The compressor 1 includes a tooth portion 112a that forms a compression chamber 151 between the compressor 12 and the fixed scroll 12. The intermediate pressure refrigerant is sucked into the compression chamber 151 through a discharge hole (refrigerant suction port) 127 due to the displacement of the tooth portion 112a. Then, a high-stage compressor 151A that compresses the intermediate-pressure refrigerant in the compression chamber 151 and discharges it as a high-pressure refrigerant is provided. The compressor 1 includes an intermediate pressure flow path 142 that guides the refrigerant discharged from the low-stage compressor 152A to the refrigerant suction port of the high-stage compressor 151A, and the heat pump cycle 10 so that the high-pressure refrigerant and the low-pressure refrigerant An injection flow path 141 for injecting the intermediate pressure refrigerant generated from the first expansion valve 3 for generating an intermediate pressure refrigerant having an intermediate pressure therebetween into the intermediate pressure flow path 142 and for injecting the intermediate pressure refrigerant into the compression chamber 152A. With.

  As described above, the injection is performed not in the compression chamber 151A of the high stage compressor 151A but in the compression chamber 152A of the low stage compressor 152A.

  Here, the refrigerant pressure of the gas-phase refrigerant in the gas-liquid separator 4 is higher than the refrigerant pressure in the compression chamber 152A of the low-stage compressor 152A. Then, since the intermediate pressure refrigerant is injected from the gas-liquid separator 4 into the intermediate pressure flow path 142 and the compression chamber 152, it is possible to secure the refrigerant amount of the intermediate pressure refrigerant injected into the compressor. Therefore, COP (Coefficient Of Performance) of the heat pump cycle 100 can be improved.

  The sealed casing that houses the high-stage compressor, the low-stage compressor, and the electric motor section of Patent Document 1 is filled with intermediate pressure refrigerant. For this reason, the circumference | surroundings of an electric motor part are filled with the high temperature refrigerant | coolant.

  In contrast, the housing 30 that houses the electric motor unit 20 of the present embodiment is filled with low-pressure refrigerant. For this reason, the low temperature refrigerant | coolant is satisfy | filled the circumference | surroundings of the electric motor part 20. FIG. Therefore, since the electric motor unit 20 can be cooled, the motor efficiency of the electric motor unit 20 can be improved, and the COP of the heat pump cycle 100 can be further improved.

  The housing 30 of this embodiment is filled with a low-pressure refrigerant. For this reason, since the thickness of the housing 30 can be reduced as compared with the case where the housing 30 is filled with the intermediate pressure refrigerant, the weight can be reduced and the cost can be reduced.

  In the compressor of the above-mentioned patent document 1, since the compression mechanism is configured on both sides in the axial direction of the electric motor unit, the assembly of the compressor becomes complicated, which is disadvantageous in terms of cost.

  On the other hand, in the compressor 1 of the present embodiment, the compression mechanism unit 10 is configured on one axial side of the electric motor unit 20. Assembling of the compressor 1 is simplified, which is advantageous in terms of cost.

  In the compressor of Patent Document 1, the first refrigerant path for injecting the intermediate stage refrigerant flowing between the refrigerant outlet of the first pressure reducing valve and the refrigerant inlet of the second pressure reducing valve into the working chamber of the high stage side compressor; And a second refrigerant path for injecting an intermediate stage refrigerant flowing between the refrigerant outlet of the second pressure reducing valve and the refrigerant inlet of the third pressure reducing valve into the case. For this reason, it is necessary to assemble two refrigerant pipes into the case in order to supply the intermediate-stage refrigerant into the compressor.

  On the other hand, the check valve 60 is disposed between the intermediate pressure inflow port 30b and the intermediate pressure flow path 142 in the housing 30 of the compressor 1 of the present embodiment. For this reason, the refrigerant flow path that is diverted from the injection flow path 141 and flows the intermediate pressure refrigerant to the intermediate pressure flow path 142 is disposed in the housing 30. Therefore, in order to supply the intermediate pressure refrigerant to the compression chamber 152A and the intermediate pressure flow path 142 of the compressor 1, one intermediate pressure refrigerant pipe INJ is used. Therefore, the compressor 1 of this embodiment can reduce the number of intermediate pressure refrigerant pipes assembled to the housing 30. Therefore, the assembly is simplified, which is advantageous in terms of cost.

  In the present embodiment, the electronic control device (not shown) controls the first expansion valve 3 and the second expansion valve 5, thereby reducing the intermediate pressure refrigerant pressure flowing from the gas-liquid separator 4 to the injection flow path 141. Can be set. For this reason, the magnitude relationship between the refrigerant pressure in the injection flow channel 141 and the refrigerant pressure in the intermediate pressure flow channel 142 can be set. That is, by controlling the first and second expansion valves 3 and 5, the refrigerant pressure in the intermediate pressure channel 142 can be made larger than the refrigerant pressure in the injection channel 141.

  Thereby, the magnitude relationship between the refrigerant pressure in the injection flow path 141 and the refrigerant pressure in the intermediate pressure flow path 142 can be set, and the check valve 60 can be opened and closed. Therefore, by controlling the first and second expansion valves 3 and 5, the intermediate pressure refrigerant from the injection flow channel 141 can be selectively injected into the intermediate pressure flow channel 142 and the compression chamber 152.

  That is, the first state in which the intermediate pressure refrigerant is injected into the intermediate pressure flow path 142 and the compression chamber 152 and the second state in which the intermediate pressure refrigerant is injected into the compression chamber 152 can be switched. Thereby, the performance can be improved in a wide range of operating conditions from a low compression ratio to a high compression ratio in the compressor 1.

  A check valve 60 is disposed between the intermediate pressure inflow port 30b and the intermediate pressure flow path 142 of the compressor 1 of the present embodiment. For this reason, it can suppress that a refrigerant | coolant flows backward from the intermediate pressure flow path 142 to the intermediate pressure inflow port 30b side. Therefore, the COP of the heat pump cycle 100 can be further improved.

  A check valve 51 is disposed between the intermediate pressure inflow port 30 b and the compression chamber 152 of the compressor 1 of the present embodiment. For this reason, it is possible to stop the refrigerant from flowing backward from the compression chamber 152 to the intermediate pressure inflow port 30b side. Therefore, the COP of the heat pump cycle 100 can be further improved.

(Second Embodiment)
In the second embodiment, an example in which the pressure adjusting valve 70 is provided between the refrigerant outlet of the intermediate pressure inflow port 30b and the refrigerant inlet of the check valve 51 in the compressor 1 of the first embodiment will be described.

  FIG. 8 shows a cross-sectional structure of the pressure regulating valve 70 of this embodiment and its periphery.

  The pressure regulating valve 70 is disposed in a recess 14 a that opens upward in the discharge plate 14. The pressure adjustment valve 70 is a mechanical pressure adjustment valve including a valve body 71, a valve housing 72, and a spring 73.

  The valve housing 72 houses the valve body 71. A suction hole 75 that communicates between the inside of the valve housing 72 and the injection flow path 141 is provided on a side surface of the valve housing 72.

  A discharge hole 76 that communicates between the inside of the valve housing 72 and the check valve 51 side is provided on the upper side of the valve housing 72. The discharge hole 76 depressurizes the intermediate pressure refrigerant flowing from the inside of the valve housing 72 to the check valve 51 side. The valve body 71 is provided with a conical portion 71a whose upper side is formed in a conical shape.

  The conical portion 71a adjusts the opening area of the discharge hole 76 by its vertical displacement. Specifically, the opening area of the discharge hole 76 is reduced by the upward displacement of the conical portion 71a. On the other hand, when the conical portion 71a is displaced downward, the opening area of the discharge hole 76 is enlarged.

  The spring 73 is disposed between the valve body 71 and the bottom of the recess 14 a of the discharge plate 14. The elastic force of the spring 73 is applied to the valve body 71. A communication hole 74 communicates with the recess 14a.

  The communication hole 74 communicates with the suction port 30a. For this reason, the pressure of the low-pressure refrigerant flowing from the suction port 30a through the communication hole 74 and the elastic force of the spring 73 are applied to the bottom of the valve body 71.

  On the other hand, intermediate pressure refrigerant flowing through the suction hole 75 flows between the ceiling surface of the valve housing 72 and the valve body 71. For this reason, the valve body 71 is displaced in the vertical direction by the pressure difference between the pressure of the low-pressure refrigerant and the elastic force of the spring 73 and the pressure of the intermediate-pressure refrigerant. Along with this, the conical portion 71a adjusts the opening area of the discharge hole 76 by its vertical displacement. For this reason, the valve body 71 adjusts the pressure of the intermediate pressure refrigerant flowing from the inside of the valve housing 72 to the check valve 51 side.

  As described above, the amount of refrigerant throttled by the valve body 71 and the discharge hole 76 can be adjusted.

  In the present embodiment, by adjusting the elastic force of the spring 73 and the refrigerant pressure applied to the bottom of the valve body 71, the throttle amount of the refrigerant throttled by the valve body 71 and the discharge hole 76 is set to an arbitrary value. be able to.

(Third embodiment)
In the first and second embodiments, the example in which the gas-liquid separator 4 and the intermediate pressure inflow port 30b of the compressor 1 are connected by the intermediate pressure refrigerant pipe INJ has been described. Thus, the refrigerant outlet of the water-refrigerant heat exchanger 2 and the refrigerant inlet of the second expansion valve 5 are connected by a refrigerant pipe, and between the refrigerant outlet of the water-refrigerant heat exchanger 2 and the intermediate pressure inlet port 30b. The first expansion valve 3A may be connected to the first expansion valve 3A.

(Fourth embodiment)
In the fourth embodiment, in the compression chamber 1 of the third embodiment, as shown in FIG. 10, the pressure regulating valve 70 </ b> A is provided between the refrigerant outlet of the intermediate pressure inflow port 30 b and the refrigerant inlet of the check valve 51. May be arranged.

  In the pressure adjusting valve 70A, the refrigerant pressure of the intermediate pressure refrigerant flowing from the intermediate pressure inflow port 30b through the check valve 51 to the compression chamber 152 is higher than the refrigerant pressure of the low pressure refrigerant flowing from the evaporator 6 to the compression chamber 152 by a certain pressure. The refrigerant pressure of the intermediate pressure refrigerant flowing from the intermediate pressure inflow port 30b to the compression chamber 152 through the check valve 51 is adjusted so that the pressure becomes the pressure.

  As a result, the intermediate pressure refrigerant can be injected from the gas-liquid separator 4 into the intermediate pressure flow path 142 and the compression chamber 152 in a well-balanced manner, so that the flow rate of the injected refrigerant is increased corresponding to various pressure conditions. And COP can be improved.

(Other embodiments)
(1) In the first to fourth embodiments, the example in which the compressor 1 is arranged so that the axial direction of the drive shaft 25 extends in the up-down direction DR1 is described. However, the present invention is not limited thereto, and the axial direction of the drive shaft 25 is changed. You may arrange | position the compressor 1 so that it may cross | intersect the up-down direction DR1.

  (2) In the first to fourth embodiments, examples in which the movable scroll 11 of the compression mechanism unit 10 is provided with the tooth portions 112a and 112b protruding downward from one surface (the lower surface in FIG. 3) of the substrate portion 111 will be described. However, instead of this, the following may be used.

That is, in the movable scroll 11, a tooth portion 112 a that protrudes downward from the lower surface of the substrate portion 111 and a tooth portion 112 b that discharges upward from the upper surface of the substrate portion 111 are configured. In this case, an upper fixed scroll that forms a compression chamber 151 between the tooth portion 112a of the substrate portion 111,
It is necessary to provide a lower fixed scroll that forms the compression chamber 152 between the tooth portion 112 b of the substrate portion 111.

  Of course, the tooth part 112b protruding upward from the upper surface of the substrate part 111 and the tooth part 112a discharging downward from the lower surface of the substrate part 111 may be configured.

  (3) In the first to fourth embodiments, the example in which the branch refrigerant flow path that branches from the injection flow path 141 and flows the intermediate pressure refrigerant to the intermediate pressure flow path 142 is disposed in the housing 30 has been described. Thus, the branch refrigerant flow path may be disposed outside the housing 30.

  (4) In the first to fourth embodiments, the example in which the two compression chambers 151 and 152 are configured by the pair of movable scrolls 11 and the fixed scroll 12 has been described, but instead of this, two pairs of movable scrolls Two compression chambers 151 and 152 may be configured by the fixed scroll.

  In other words, in the first to fourth embodiments, the example in which the fixed scroll 12 is used as the common fixed portion that forms the compression chambers 151 and 152 has been described. You may employ | adopt a scroll and a 2nd movable scroll, and may employ | adopt the 1st fixed scroll and the 2nd fixed scroll which were mutually independent.

  In this case, the compression chamber 151 may be configured by the first movable scroll and the first fixed scroll, and the compression chamber 152 may be configured by the second movable scroll and the second fixed scroll.

  (5) In the above first to fourth embodiments, the example in which the scroll type compressor is used as the compressor of the present invention has been described, but instead of this, a rotary type compressor other than the scroll type compressor, Various compressors such as a vane compressor may be used as the compressor of the present invention.

  In this case, a first compressor and a second compressor that are independent from each other may be employed, the compression chamber 151 may be configured by the first compressor, and the compression chamber 152 may be configured by the second compressor. In the case of a compressor other than the scroll type compressor, the compression chambers 151 and 152 may be configured in one compressor.

  (6) In the first to fourth embodiments, the example in which the check valve having the free valve 61 is used as the check valve 60 has been described, but instead of this, a reed valve type reverse valve is used as the check valve 60. Various check valves such as a stop valve may be used.

  (7) In the first to fourth embodiments, the example in which the reed valve type check valve is used as the check valve 51 has been described. Instead, the check valve 60 has a free valve 61 as a check valve. Various check valves such as a stop valve may be used.

  (8) In the above first to fourth embodiments, an example in which a mechanical pressure adjustment valve is used as the pressure adjustment valve 70 has been described. Instead, an electromagnetic valve, an electric valve, or the like is used as the pressure adjustment valve 70. May be.

  (9) It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims. Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily indispensable except for the case where it is clearly indicated that the element is essential and the case where the element is clearly considered essential in principle. Yes. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

(Summary)
According to the first aspect described in part or all of the first, second, third, fourth embodiment, and other embodiments, the compressor is applied to a refrigeration cycle in which a refrigerant is circulated. A first movable portion that forms a first compression chamber between the fixed portion and the fixed portion, and the first compression is performed by sucking the low-pressure refrigerant into the first compression chamber by displacement of the first movable portion. A low-stage compressor that compresses low-pressure refrigerant in a room and discharges it as a compressed refrigerant, a second fixed member, and a second movable part that forms a second compression chamber between the second fixed member, A high-stage compressor that sucks compressed refrigerant through a refrigerant suction port into the second compression chamber by displacement of the second movable portion, compresses the compressed refrigerant in the second compression chamber, and discharges the compressed refrigerant as a high-pressure refrigerant; and a low-stage compressor An intermediate pressure passage for guiding the compressed refrigerant discharged from the refrigerant suction port of the high-stage compressor, and a refrigeration cycle The intermediate pressure refrigerant generated from the decompression unit that generates intermediate pressure refrigerant having an intermediate pressure between the high pressure refrigerant and the low pressure refrigerant is injected into the intermediate pressure flow path, and the intermediate pressure refrigerant is And an injection flow path for injection.

  According to the 2nd viewpoint, the 1st non-return valve which suppresses that a refrigerant | coolant flows back to the pressure reduction part side through an injection flow path from a 1st compression chamber is provided.

  Thereby, COP in a refrigerating cycle can be improved.

  According to the 3rd viewpoint, the 2nd non-return valve which suppresses that a refrigerant | coolant flows backward to the pressure reduction part side through an injection flow path from an intermediate pressure flow path is provided.

  Thereby, COP in a refrigerating cycle can be improved.

  According to the 4th viewpoint, the pressure regulation valve which adjusts the pressure of the refrigerant | coolant which flows into a 1st compression chamber through an injection flow path from a pressure reduction part is provided.

  According to the fifth aspect, the low-stage compressor, the high-stage compressor, the case that houses and seals the intermediate pressure flow path, and the intermediate pressure refrigerant pipe that guides the intermediate pressure refrigerant from the decompression section to the case The injection flow path is disposed in the sealed case and divides the intermediate pressure refrigerant that has passed through the intermediate pressure refrigerant pipe into the intermediate pressure path and the first compression chamber.

  Thereby, in order to guide the intermediate pressure refrigerant into the case, one intermediate pressure refrigerant pipe is used. For this reason, since the intermediate pressure refrigerant is guided into the case, the configuration can be simplified.

  According to the sixth aspect, the electric motor having the output shaft and outputting the rotational force to the output shaft is provided, and the low-stage compressor and the high-stage compressor are arranged on one side in the axial direction of the output shaft. The first movable part of the low-stage compressor and the second movable part of the high-stage compressor are driven and displaced by the rotational force of the output shaft.

  This simplifies the configuration as compared with the case where the low-stage compressor is arranged on one side of the output shaft in the axial direction and the high-stage compressor is arranged on the other side of the output shaft in the axial direction. Can do.

  According to the seventh aspect, the first movable portion and the second movable portion are configured to be capable of swiveling around the center line and extend in a direction crossing the center line, and project from one surface of the substrate. A scroll-type compression mechanism including a tooth portion formed in a spiral shape is configured, and the first movable portion and the second movable portion are displaced by the swiveling motion of the substrate and the tooth portion.

  According to the eighth aspect, the first movable portion and the second movable portion include a first tooth portion and a second tooth portion as tooth portions protruding from one surface of the substrate.

  Thereby, since the first movable part and the second movable part can be configured using a common substrate, the first movable part and the second movable part can be reduced in size.

  According to the ninth aspect, the first movable portion and the second movable portion protrude from a surface of the substrate opposite to the first tooth portion as a tooth portion protruding from one surface of the substrate, and from one surface of the substrate. And a second tooth portion formed in a spiral shape.

  Thereby, since the first movable part and the second movable part can be configured using a common substrate, the first movable part and the second movable part can be reduced in size.

  According to the tenth aspect, the case is filled with the low-pressure refrigerant.

  Thereby, since the circumference | surroundings of an electric motor can be satisfy | filled with a low voltage | pressure refrigerant | coolant, an electric motor can be cooled.

  According to an eleventh aspect, the refrigerant contains carbon dioxide.

DESCRIPTION OF SYMBOLS 1 Compressor 3 1st expansion valve 5 2nd expansion valve 10 Compression mechanism part 20 Electric motor part 30 Housing 100 Heat pump cycle 112a, 112b Tooth part 141 Injection flow path 142 Intermediate pressure flow path 152, 151 Compression chamber 151A High stage side compressor 152A Low stage compressor

Claims (11)

A compressor applied to a refrigeration cycle (100) for circulating refrigerant,
A fixed portion (12) and a first movable portion (111, 112b) forming a first compression chamber (152) between the fixed portion and a displacement of the first movable portion are provided in the first compression chamber. A low-stage compressor (152A) that sucks low-pressure refrigerant into the first compression chamber and compresses the low-pressure refrigerant to be discharged as compressed refrigerant;
A fixed part (12) and a second movable part (111, 112a) that forms a second compression chamber (151) between the fixed part (12) and a displacement of the second movable part are provided. A high-stage compressor (151A) that sucks the compressed refrigerant through the refrigerant suction port (127), compresses the compressed refrigerant in the second compression chamber, and discharges the compressed refrigerant as a high-pressure refrigerant;
An intermediate pressure flow path (142) for guiding the compressed refrigerant discharged from the low-stage compressor to the refrigerant suction port of the high-stage compressor;
The intermediate pressure refrigerant generated from the decompression section (3, 3A) that constitutes the refrigeration cycle and generates an intermediate pressure refrigerant having an intermediate pressure between the high pressure refrigerant and the low pressure refrigerant is injected into the intermediate pressure flow path. And an injection flow path (141) for injecting the intermediate pressure refrigerant into the first compression chamber.   2. The compressor according to claim 1, further comprising a first check valve (51) that suppresses a reverse flow of the refrigerant from the first compression chamber to the decompression unit side through the injection flow path.   The compressor according to claim 1 or 2, further comprising a second check valve (60) for suppressing a refrigerant from flowing backward from the intermediate pressure channel to the decompression unit side through the injection channel.   The compressor according to any one of claims 1 to 3, further comprising a pressure adjusting valve (70, 70A) that adjusts a pressure of a refrigerant flowing from the decompression unit through the injection flow path into the first compression chamber. A case (30) that houses and seals the low-stage compressor, the high-stage compressor, and the intermediate pressure flow path;
An intermediate pressure refrigerant pipe (INJ) for guiding the intermediate pressure refrigerant from the decompression section to the case, and
5. The injection path according to claim 1, wherein the injection flow path is disposed in the sealed case and divides the intermediate pressure refrigerant that has passed through the intermediate pressure refrigerant pipe into the intermediate pressure flow path and the first compression chamber. Compressor described in 1. An electric motor (20) having an output shaft (25) and outputting a rotational force to the output shaft;
The low-stage compressor and the high-stage compressor are disposed on one side in the axial direction of the output shaft,
The first movable portion of the low-stage compressor and the second movable portion of the high-stage compressor are driven and displaced by the rotational force of the output shaft. The compressor described in 1. The first movable portion and the second movable portion are configured to be capable of swiveling around a center line and spread in a direction intersecting the center line, and a spiral protruding from one surface of the substrate. A scroll-type compression mechanism including tooth portions (112a, 112b) formed in a shape,
The compressor according to any one of claims 1 to 6, wherein the first movable portion and the second movable portion are displaced by the swivel movement of the substrate and the tooth portion.   The said 1st movable part and the said 2nd movable part are provided with the 1st tooth | gear part (112a) and the 2nd tooth | gear part (112b) as the said tooth part which protrude from one surface of the said board | substrate. Compressor.   The first movable portion and the second movable portion are a first tooth portion as the tooth portion protruding from one surface of the substrate and a spiral shape protruding from a surface of the substrate opposite to the one surface. The compressor according to claim 7 provided with the 2nd tooth part currently formed in.   The compressor according to any one of claims 6 to 8, wherein the case is filled with the low-pressure refrigerant.   The compressor according to any one of claims 1 to 10, wherein the refrigerant contains carbon dioxide.

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