JP4556934B2 - Compressor and refrigerant circuit device - Google Patents

Description

  The present invention relates to a compressor that compresses a refrigerant by a two-stage compression type compression mechanism section including a low-stage compression mechanism section and a high-stage compression mechanism section, and a refrigerant circuit device using the compressor.

  A conventional two-stage compression type refrigerant circuit device includes a compression mechanism unit including a low-stage compression mechanism unit and a high-stage compression mechanism unit in an airtight container, and an electric motor that drives the compression mechanism unit. Open the low-stage discharge pipe of the side compression mechanism section into the sealed container, and discharge the intermediate-pressure refrigerant compressed by the low-stage compression mechanism section into the sealed container to create an intermediate pressure atmosphere in the sealed container. An internal intermediate pressure type two-stage compressor in which the high-stage suction pipe of the compression mechanism is opened in a sealed container of the intermediate pressure atmosphere, a high-pressure side heat exchanger such as a condenser and a gas cooler, and an expansion valve A refrigeration circuit is configured by connecting a throttling device for decompression and a low-pressure side heat exchanger such as an evaporator, and a low-stage suction pipe and a low-pressure side heat exchanger outlet of the low-stage compression mechanism And connect the high-stage discharge pipe of the high-stage side compression mechanism to the high-pressure side heat exchanger and the high-pressure side heat exchanger The branch pipe branched from the connecting pipe between the mouth and the diaphragm device, the upper part of the sealed container of the compressor, is connected to the closed vessel in communication with the interior.

  With the above configuration, a part of the refrigerant between the high-pressure side heat exchanger outlet and the expansion device is injected into the sealed container via the branch pipe, and cools the electric motor with its latent heat when passing through the electric motor, After cooling the electric motor, the refrigerant is sucked into the high-stage side compression mechanism part from the high-stage suction pipe opened inside the sealed container together with the refrigerant discharged from the low-stage side compression mechanism part, and is compressed to the discharge pressure there. Then, it is led to the high-pressure side heat exchanger inlet (see, for example, Patent Document 1).

JP-A-2-133757 (page 2-3, FIG. 1)

  In a conventional two-stage compression type refrigerant circuit device using an internal intermediate pressure type two-stage compressor, the refrigerant circuit was injected into the hermetic container of the compressor from between the high-pressure side heat exchanger outlet and the low-pressure side heat exchanger inlet. The refrigerant (hereinafter referred to as injection refrigerant) passes through the electric motor and cools the electric motor. The injection refrigerant after passing through the electric motor and the intermediate discharged from the low stage discharge pipe of the low stage compression mechanism into the sealed container The refrigerant discharged under pressure is introduced directly into the high-stage suction pipe that opens into the sealed container by the suction action of the high-stage compression mechanism, so there is not enough heat exchange between the refrigerants. There is a possibility that the refrigerant will be sucked into the high-stage compression mechanism portion without being mixed and in a state where the weight ratio of the refrigerant groups is not constant.

While the pressure is instantaneously equalized in the sealed container, the temperatures of the two refrigerants do not instantly become equal, so there is a density difference between the two refrigerant groups. Since the injected refrigerant passes through the high-pressure side heat exchanger, the temperature tends to be low and the density tends to be high although the motor is cooled. Therefore, the refrigerant taken in every compression stroke in the stroke volume of the high-stage compression mechanism section includes two refrigerants having different temperatures and densities, ie, the injected refrigerant after passing through the electric motor and the refrigerant discharged from the low-stage compression mechanism section. There is a group, and the high-stage compression mechanism is sucked in such a state that the ratio of the two refrigerant groups is different for each compression stroke. Further, when the jet refrigerant includes a liquid refrigerant, it may not be completely gasified even when it passes through the electric motor, and a part thereof may be sucked into the high-stage compression mechanism section in a liquid state.

As described above, the heat exchange between the injected refrigerant after passing through the motor and the refrigerant discharged from the low-stage compression mechanism section is not sufficiently performed before being sucked into the high-stage compression mechanism section, so that the high-stage compression mechanism section Since the refrigerant sucked in is in a state in which the ratio of the two refrigerant groups is different for each compression stroke, the apparent density of the refrigerant taken in becomes unstable in each compression stroke. Since the mass flow rate of the refrigerant at the discharge pressure discharged from the side compression mechanism is not stable, the operation characteristics of the refrigerant circuit device are not stable, and the compressor also has problems such as vibration and noise due to discharge pulsation.

  The present invention has been made to solve the above-described problems. In the refrigerant circuit device using the internal intermediate pressure type two-stage compressor, the refrigerant between the high-pressure side heat exchanger outlet and the expansion device is used. Even if it is injected into the airtight container of the compressor and the electric motor arranged in the airtight container is cooled, the heat exchange between the injected refrigerant after cooling the electric motor and the refrigerant discharged from the low-stage compression mechanism section is sufficient. Thus, a compressor in which the density of the refrigerant sucked into the high-stage compression mechanism is stabilized and a refrigerant circuit device using the compressor are obtained.

  In the compressor according to the present invention, an airtight container that accommodates therein an electric motor, a low-stage compression mechanism that is driven by a rotary shaft connected to the electric motor, and a compression mechanism that includes a high-stage compression mechanism. One end is opened in the space between the motor on the anti-compression mechanism portion side of the electric motor and the sealed container, the injection pipe for injecting the refrigerant from the outside of the sealed container into the sealed container, and the lower stage compression mechanism portion A low-stage discharge pipe for discharging the refrigerant into the sealed container, and one end opened in a space between the electric motor and the compression mechanism, and the refrigerant injected from the injection pipe and the refrigerant discharged from the low-stage discharge pipe are sealed in the sealed container And a high-stage intake pipe that is connected to the other end of the refrigerant discharge pipe and sucks the refrigerant extracted from the refrigerant discharge pipe to the high-stage compression mechanism. .

According to this invention, the process in which the injection refrigerant after passing through the electric motor and the discharge refrigerant of the low-stage compression mechanism section pass through the pipe through which the intermediate-pressure refrigerant outside the sealed container reaches the high-stage compression mechanism section. Can sufficiently exchange heat with each other, and the two refrigerant groups can be equalized in temperature and density to become one refrigerant group before being sucked into the high-stage compression mechanism section. In this state, the density of the refrigerant sucked into the high-stage compression mechanism is stable, and the mass flow rate of the refrigerant at the discharge pressure discharged from the high-stage compression mechanism is also stable. And the generation of compressor vibration and noise caused by unstable discharge mass flow rate can be avoided. Furthermore, even if there is jet refrigerant that is not gasified even after passing through the electric motor, it is completely gasified by heat exchange with the refrigerant discharged from the low-stage compression mechanism, so the high-stage compression A situation in which the liquid refrigerant is sucked into the mechanism part can be avoided. Therefore, a highly efficient and highly reliable compressor is obtained, and a refrigerant circuit device using this compressor is also highly efficient and highly reliable.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a two-stage compression refrigerant circuit device according to Embodiment 1 for carrying out the present invention. In this embodiment, a heat pump type hot water supply device is used, and carbon dioxide is used as a refrigerant. ing. FIG. 2 is an explanatory view showing the periphery of the internal intermediate pressure type two-stage compressor 1 (hereinafter referred to as the compressor 1) used in the refrigerant circuit device. The compressor 1 is a two-stage compression type comprising a low-stage compression mechanism 11 (hereinafter referred to as a low-stage section 11) and a high-stage compression mechanism 12 (hereinafter referred to as a high-stage section 12) in an airtight container 10. A compression mechanism section and an electric motor 13 that rotates these compression mechanism sections 11 and 12 via a rotation shaft 14 are provided. Two-stage compression type compression mechanism portions 11 and 12 are disposed below the electric motor 13, the low-stage portion 11 is disposed on the bottom side of the sealed container 10, and the high-stage portion 12 is disposed above the low-stage portion 11.

  The sealed container 10 is hermetically sealed by joining an upper lid 10b and a bottom lid 10c to a cylindrical container 10a that is open at the top and bottom by welding or the like. The sealed container 10 may have a two-part configuration in which the top lid 10b is joined to a bottomed cylindrical container formed by drawing or the like. An oil sump 17 is provided at the bottom of the sealed container 10 to store lubricating oil used for lubricating and sealing the compression mechanism.

The electric motor 13 includes a stator 13a and a rotor 13b. In the outer periphery of the rotor 13b and the inner periphery of the stator 13a, a radial clearance called an air gap is provided substantially uniformly over the entire periphery. Although not shown, the stator 13a has a coil wound around the inner teeth of a substantially annular magnetic steel sheet laminated in a concentrated winding manner, and the outer periphery of the laminated electromagnetic steel sheet is shrink-fitted to the inner periphery of the sealed container 10. It is fixed by. Since a plurality of cutouts are partially provided on the outer periphery of the electromagnetic steel plates on which the stator 13a is laminated, the upper and lower sides of the stator 13a are formed between the inner periphery of the hermetic container 10 and the outer periphery of the stator 13a by the cutouts. Is formed.

Although the rotor 13b is not shown in the drawing, like the stator 13a, an annular electromagnetic steel plate is laminated, and permanent magnets such as rare earth magnets and ferrite magnets are embedded in the electromagnetic steel plate, and the laminated electromagnetic steel plate A plurality of air holes are provided as flow paths so as to communicate vertically. In the rotor 13b, the inner periphery of the laminated electromagnetic steel sheets is shrink-fitted with the rotating shaft 14, and when electric power is supplied to the stator 13a, the rotating shaft 14 rotates integrally with the rotor 13b. Although not shown, a glass terminal is welded and fixed to the upper lid 10b of the sealed container 10, the glass terminal and the stator 13a are connected by lead wires, and electric power supplied from outside relays the glass terminal to the motor. 13.

Each of the low-stage part 11 and the high-stage part 12 includes a rotary compression mechanism that performs compression by reducing the volume of the compression chamber partitioned from the suction chamber by the vane while the roller rotates eccentrically in the cylinder. The compression chambers of the low step portion 11 and the high step portion 12 are separated by a partition plate arranged between the low step portion 11 and the high step portion 12. When electric power is supplied to the electric motor 13 and the rotary shaft 14 is driven to rotate by the electric motor 13, a refrigerant having a suction pressure (low pressure) is sucked from the low-stage suction pipe 20 into the low-stage portion 11. Then, it is compressed to an intermediate pressure in the low stage portion 11, and from the low stage discharge pipe 21 that opens into the space A 31 that is a space between the electric motor 13 and the high stage section 12 that is the compression mechanism section in the sealed container 10. 10 is discharged in its entirety. Thereby, the inside of the sealed container 10 becomes an intermediate pressure atmosphere.

The intermediate-pressure refrigerant in the hermetic container 10 is temporarily sealed from the refrigerant outlet tube 22 that is installed on the wall of the hermetic container 10 facing the space A31 between the electric motor 13 and the high stage portion 12 and opens at one end inside the hermetic container 10. It is led out of the container 10. The refrigerant outlet pipe 22 is installed in a direction approximately 180 ° symmetrical to the direction of the position where the low-stage discharge pipe 21 is opened with the rotation axis 14 as the center. The intermediate pressure refrigerant is sequentially passed through an intermediate pressure connection pipe 25 and a high stage suction pipe 23, one end of which is connected to the refrigerant outlet pipe 22 and the other end connected to the high stage suction pipe 23. Then, it is sucked into the high stage part 12, compressed to the discharge pressure (high pressure) at the high stage part 12, and directly passes through the high stage discharge pipe 24 from the high stage part 12 without being opened into the sealed container. It is discharged to the connection pipe A40 of the refrigerant circuit device outside the sealed container 10. The intermediate pressure connection pipe 25 is formed by bending a single pipe, but may be formed by connecting a plurality of pipes.

  In the figure, the intermediate pressure connecting pipe 25 is provided across the upper lid 10b. However, the intermediate pressure refrigerant discharged from the refrigerant discharge pipe 22 does not impair the compactness of the compressor 1, and the high pressure suction is performed. The upper lid 10b is straddled so that the distance until it is sucked into the high step portion 12 through the tube 23 can be taken as long as possible. The intermediate pressure connection pipe 25 is not limited to this shape, and may be provided so as to crawl the outside of the cylindrical container 10a, and the intermediate pressure refrigerant discharged from the refrigerant discharge pipe 22 is sucked into the high stage portion 12. In order to lengthen the distance until the end of the cylindrical container 10a, the outer side of the cylindrical container 10a may be circulated more than half a round.

Further, in order to increase the distance until the intermediate pressure refrigerant discharged from the refrigerant discharge pipe 22 is sucked into the high stage portion 12 without hindering the compactness of the compressor 1, the refrigerant outlet pipe 22 and the high stage The phase of the suction pipe 23 should be largely shifted between a maximum of 180 °. However, even if the phase difference between the refrigerant outlet pipe 22 and the high-stage suction pipe 23 is small, the shape and arrangement of the intermediate pressure connection pipe 25 are, for example, By appropriately setting the outer circumference of the cylindrical container 10a, for example, until the medium-pressure refrigerant discharged from the refrigerant discharge pipe 22 is sucked into the high stage portion 12 without impairing the compactness of the compressor 1. The distance can be set longer.

Further, without either the intermediate pressure connection pipe 25, either the refrigerant outlet pipe 22 or the high stage suction pipe 23 is formed long, or each of the refrigerant outlet pipe 22 and the high stage suction pipe 23 is formed long and directly. The cold lead-out pipe 22 and the high stage suction pipe 23 may be connected. The connection of the refrigerant outlet pipe 22 and the high stage suction pipe 23 includes the case of connecting via the intermediate pressure connection pipe 25 in the middle and the case of connecting both pipes 22 and 23 directly. Further, the refrigerant outlet pipe 22 and the intermediate pressure connecting pipe 25 may be collectively determined as a refrigerant outlet pipe, or the intermediate pressure connecting pipe 25 and the high stage suction pipe 23 may be collectively determined as a high stage suction pipe.

In the upper part of the compressor 1, that is, the upper cover 10 b of the sealed container 10, there is a space B 32 that is on the side opposite to the compression mechanism part of the electric motor 13 inside the sealed container 10 and is a space between the electric motor 13 and the upper cover 10 b of the sealed container 10. One end is opened, and an injection pipe 26 for injecting refrigerant from the outside of the sealed container 10 into the space B32 is installed. In FIG. 2, the injection pipe 26 is installed in a direction parallel to the axial direction of the compressor 1 and has a straight pipe shape. However, if one end opens in the space B <b> 32 which is the upper part of the electric motor 13, the injection pipe 26 is injected. The pipe 26 may have any direction and shape, and may be installed on the side surface of the sealed container 10 in a direction orthogonal to the axial direction of the compressor 1. One end of the injection pipe 26 opens into the space B32 as described above, and the other end is connected to the branch pipe B51 of the refrigerant circuit device. Similarly to the low-stage discharge pipe 21, the injection pipe 26 is installed in a direction approximately 180 ° symmetrical to the direction in which the refrigerant outlet pipe 22 is located around the axis of the rotating shaft 14.

  Next, a heat pump hot water supply apparatus that is a two-stage compression refrigerant circuit apparatus using the compressor 1 will be described with reference to FIG. The high-pressure discharge gas 24 discharged from the compressor 1 is connected to the high-stage discharge pipe 24 of the compressor 1 with the other end of the connection pipe A40 connected at one end to the inlet of the high-pressure side heat exchanger 2 that is a gas cooler. Is introduced into the high-pressure side heat exchanger 2 via the connection pipe A40. In FIG. 1, the high-pressure side heat exchanger 2 is a gas cooler. Here, the high-pressure refrigerant flows in the reverse direction in the water pipe 62 passing through the same high-pressure side heat exchanger 2 against the refrigerant flow by the pump 61. Heat is exchanged with the water flowing in the water to lower the temperature. On the other hand, the water in the water pipe 62 is heated by heat exchange with the refrigerant and stored in the hot water storage tank 60.

The high-pressure refrigerant whose temperature has been lowered by exchanging heat with water in the high-pressure side heat exchanger 2 that is a gas cooler is decompressed to a low pressure by the expansion device 3 that is an electronic expansion valve. The throttle device 3 controls the refrigerant flow rate of the refrigerant circuit device. Here, the entire amount of the high-pressure refrigerant that has passed through the high-pressure side heat exchanger 2 and reduced its temperature by exchanging heat with water does not pass through the expansion device 3, and some of the refrigerant is It passes through a branch pipe A50 branched from a connection pipe B41 connecting the outlet of the heat exchanger 2 and the expansion device 3, and is reduced to an intermediate pressure by a decompression device 5 connected to the branch pipe A50, and further, one end of the decompression device 5 And the other end is connected to the injection pipe 26 of the compressor 1, and the injection pipe 26 is sequentially injected into the space B 32 in the sealed container 10 of the compressor 1. The decompression device 5 uses a valve mechanism such as an expansion valve or a capillary tube. One end is connected between the high pressure side heat exchanger 2 and the expansion device 3, and the other end is connected to the injection pipe 26. The decompression device 5 is provided in the middle of 50 and 51.

The low-pressure refrigerant that has passed through the expansion device 3 passes through the connection pipe C42 and flows into the low-pressure side heat exchanger 4 that is an evaporator, where it is gasified by exchanging heat with the atmosphere. After that, the air is sucked into the low stage portion 11 from the low stage suction pipe 20 of the compressor 1. Note that the refrigerant cannot be completely gasified by the low-pressure side heat exchanger 4 and part of the refrigerant remains in the liquid state and exceeds the outlet of the low-pressure side heat exchanger 4, so that the liquid refrigerant is directly sucked into the compressor 1. An accumulator may be provided between the low pressure side heat exchanger 4 and the compressor 1 so as not to occur. The accumulator may be fixed integrally to the compressor 1.

The intermediate pressure compressed by the low stage portion 11 is discharged from the low stage discharge pipe 21 to the space A31 in the sealed container 10 and the inside of the sealed container 10 becomes an intermediate pressure refrigerant atmosphere. The intermediate pressure refrigerant compressed in the low stage portion 11 is guided to the refrigerant outlet pipe 22 by the suction action of the suction chamber of the high stage section 12, and is installed outside the sealed container 10 through the refrigerant outlet pipe 22. The intermediate pressure connecting pipe 25 and the high stage suction pipe 23 attached to the sealed container 10 are sucked into the high stage 12.

  On the other hand, the injected refrigerant branched from the connection pipe B41 and reduced in pressure to the intermediate pressure by the pressure reducing device 5 and injected into the space B32 in the hermetic container 10 of the compressor 1 is similarly sucked by the suction action of the suction chamber of the high stage portion 12. The refrigerant is led to a refrigerant outlet pipe 22 below the electric motor 13. At that time, the injected refrigerant passes through the flow path formed by the notch on the outer periphery of the stator 13a, the clearance (air gap) between the stator 13a and the rotor 13b, the flow path formed by the air holes of the rotor 13b, and the like. 13 is cooled by its latent heat. By cooling the electric motor 13, the injected refrigerant that has been in a liquid or gas-liquid two-phase state is gasified, but in some cases, some of the injected refrigerant cannot be gasified even after passing through the electric motor 13 and is in a liquid state. It can happen. When the motor 13 is cooled and the temperature is lowered, the winding resistance of the stator 13a is reduced, and the efficiency is increased. Further, when a rare earth magnet is embedded in the rotor 13b, the cooling is performed and the temperature is lowered, so that the magnetic flux density of the magnet is increased, and the efficiency is further increased.

The jet refrigerant that has cooled the electric motor 13 passes through the space A31 and is sucked into the high stage portion 12 from the refrigerant outlet pipe 22 through the high stage suction pipe 23 together with the refrigerant discharged from the low stage discharge pipe 21. Here, since the refrigerant discharged from the low-stage discharge pipe 21 and the refrigerant injected from the injection pipe 26 flow out together, the refrigerant outlet pipe 22 is low-stage discharge in order to reduce the resistance as a flow path. The inner diameter of the tube 21 and the inner diameter of the injection tube 26 are larger. The inner diameters of the intermediate pressure connecting pipe 25 and the high stage suction pipe 23 are equal to the inner diameter of the low stage discharge pipe 21.

  The space B32 above the motor 13 in which the injection refrigerant is injected across the motor 13 and the space A31 below the motor 13 from which the refrigerant compressed by the low stage portion 11 is discharged from the low stage discharge pipe 21 are the above-described motor. 13 is connected in a state where the resistance as a flow path is small due to the clearance of the flow path provided in 13, so that even if there is a slight pressure difference between the injected refrigerant and the discharged refrigerant of the low stage portion 11, the pressure can be instantaneously equalized . On the other hand, the temperature of both refrigerants does not become instantaneously equal to the pressure. Since the injected refrigerant after passing through the electric motor 13 is a refrigerant whose temperature has been lowered by the heat exchange in the high-pressure heat exchanger 2 before being injected, before the electric refrigerant 13 passes through by cooling the electric motor 13. However, in the steady operation state, the temperature is lower than the temperature of the refrigerant compressed and discharged in the low stage portion 11.

The fact that the pressure is the same but the temperature is different means that the density is different. Therefore, the injected refrigerant after passing through the electric motor 13 has a higher density than the discharged refrigerant of the low stage portion 11, and in the space A31 below the electric motor 13. The two refrigerant groups having different temperatures and densities, ie, the group of jet refrigerant after passing through the electric motor 13 and the group of refrigerant discharged from the low stage portion 11 exchange heat with each other, but are not sufficiently heat exchanged, that is, heat As a result of the replacement, the two refrigerant groups exist in a state in which the temperature and density are completely equal and do not form one refrigerant group.

However, in this compressor 1, the refrigerant sucked into the high stage portion 12 by the suction action of the high stage portion 12 is the refrigerant outlet pipe 22, the intermediate pressure connection pipe 25, and the high stage suction pipe 23 located outside the sealed container 10. Therefore, the heat exchange between the injected refrigerant after passing through the electric motor 13 and the refrigerant discharged from the low stage portion 11 can be sufficiently performed in the process of passing through the external pipe. Therefore, before being sucked into the high stage portion 12, both refrigerant groups can be equalized in temperature and density to become one refrigerant group. This is necessary for the two refrigerants to sufficiently exchange heat with each other by passing through an external pipe such as the intermediate pressure connecting pipe 25 as compared with the cited reference 1 in which the high-stage discharge pipe is opened inside the sealed container 10. It is because it gives a lot of space and time. In addition, in order to provide a space (or distance) and time necessary for sufficient heat exchange, the outside of the sealed container 10 extending from the refrigerant outlet pipe 22 such as the intermediate pressure connecting pipe 25 to the high stage portion 12 is provided. The arrangement of the pipe through which the intermediate pressure refrigerant flows is straddled over the upper lid 10b, or the outside of the cylindrical container 10a is circulated.

When the two refrigerant groups are sufficiently heat-exchanged, the temperature and density are equalized to form one refrigerant group. Therefore, in the steady operation state, the density of the refrigerant sucked into the high stage portion 12 is stable, and the compression stroke is Almost constant. The fact that the density of the sucked refrigerant is stable means that the mass flow rate of the refrigerant sucked into the high stage portion 12 is stable, and therefore the mass flow rate of the refrigerant having the discharge pressure discharged from the high stage portion 12. Therefore, the stability of the operating characteristics of the refrigerant circuit device can be improved, and the compressor vibration and noise caused by the unstable discharge mass flow rate can be avoided.

In addition, even when there is an injection refrigerant that is liquid without being gasified even when passing through the electric motor 13, in the pipe through which the intermediate pressure refrigerant outside the sealed container 10 from the refrigerant outlet pipe 22 to the high stage portion 12 flows, Since the gas is completely gasified by heat exchange with the refrigerant discharged from the low stage portion 11, a situation where the liquid refrigerant is sucked into the high stage portion 12 can be avoided. Therefore, the highly efficient and highly reliable compressor 1 is obtained, and the refrigerant circuit device using the compressor 1 is also highly efficient and highly reliable.

Embodiment 2. FIG.
FIG. 3 is an explanatory view showing the periphery of an internal intermediate pressure type two-stage compressor 6 (hereinafter referred to as the compressor 6) used in the two-stage compression refrigerant circuit device in Embodiment 2 for carrying out the present invention. . 3 that are the same as those in FIG. 2 are the same as or similar to those in the compressor 1 in FIG. 2, and a description thereof is omitted here. The compressor 6 includes a volume expanding unit 15 for expanding the space volume in which the intermediate pressure refrigerant flows in the middle of the pipe installed outside the sealed container 10 through which the intermediate pressure refrigerant sucked by the high stage unit 12 flows. Prepare. That is, the volume expanding portion 15 is provided between the refrigerant outlet tube 22 and the high stage suction tube 23. The volume expanding section 15 is larger than the inner diameter of the first intermediate pressure connecting pipe 27 having the same inner diameter as the inner diameter of the refrigerant outlet pipe 22 positioned on the inlet side of the volume expanding section 15 and is positioned on the outlet side of the volume expanding section 15. The cylindrical sealed container having an inner diameter larger than the inner diameter of the second intermediate pressure connection pipe 28 having the same inner diameter as the inner diameter of the high-stage suction pipe 23 is not limited to the cylindrical shape but may be a tank having a predetermined capacity. That's fine. In the compressor 6 shown in FIG. 3, the inner diameter of the refrigerant outlet pipe 22 and the inner diameter of the high stage suction pipe 23 are the same.

The volume expanding section 15 communicates with the first intermediate pressure connection pipe 27 connected to the refrigerant outlet pipe 22 on the inlet side and to the second intermediate pressure connection pipe 28 connected to the high stage suction pipe 23 on the outlet side. Connected to. The first intermediate pressure connection pipe 27 and the second intermediate pressure connection pipe 28 are formed by bending one pipe, but may be formed by connecting a plurality of pipes. Further, the refrigerant outlet pipe 23 may be directly connected to the volume expanding section 15 without using the first intermediate pressure connecting pipe 27, or the high stage suction pipe 23 may be connected to the volume expanding section without using the second intermediate pressure connecting pipe 28. 15 may be connected. Further, the volume expanding portion 15, the first intermediate pressure connection pipe 27, and the second intermediate pressure connection pipe 28 may be integrally formed by drawing or the like. Then, the refrigerant outlet pipe 22 and the first intermediate pressure connection pipe 27 may be collectively determined as a refrigerant outlet pipe, or the second intermediate pressure connection pipe 28 and the high stage suction pipe 23 may be collectively determined as a high stage suction pipe. May be.

  As in FIG. 2, the piping outside the sealed container 10 through which the intermediate pressure refrigerant is discharged from the refrigerant discharge pipe 22 and sucked into the high step portion 12 extends outside the cylindrical container 10a without straddling the upper lid 10b. You may provide so that it may crawl and may circle the outer side of the cylindrical container 10a. The phases of the refrigerant outlet pipe 22 and the high stage suction pipe 23 should be largely shifted between a maximum of 180 °. The volume expanding unit 15 is held by a welding or band on a receiving fixture 16 fixed to the outer peripheral surface of the cylindrical container 10 a of the sealed container 10 by welding, and is integrated with the compressor 6. The volume expansion unit 15 may be installed as a separate unit without being held by the compressor 6, but it can be made compact by being held by the compressor 6 and integrated, and the refrigerant circuit device is housed in the housing. This is advantageous.

In FIG. 3, the volume expanding portion 15 is installed on the side closer to the high stage suction pipe 23, but this position is not limited to this, and may be on the side closer to the refrigerant outlet pipe 22. The volume expanding section 15 is provided between the refrigerant outlet pipe 22 and the high stage suction pipe 23, and it is used for the sealed container 10 until the intermediate pressure refrigerant discharged from the refrigerant outlet pipe 22 is sucked into the high stage section 12. This means that it may be provided at any location in the middle of the piping that flows outside. The volume of the volume expanding section 15 is at least twice the stroke volume of the low stage section 12, and the upper limit is a volume that allows the outer shape to be held integrally with the compressor 6. The embodiment of the refrigerant circuit device on which the compressor 6 is mounted is similar to the refrigerant circuit device shown in FIG. 1, and the compressor 1 is changed to the compressor 6 in FIG. Description is omitted.

In the compressor 6 of FIG. 3, the volume expansion section 15 between the refrigerant outlet pipe 22 and the high stage suction pipe 23, which is in the middle of the piping outside the sealed container 10 through which the intermediate pressure refrigerant sucked by the high stage section 12 flows. Since the internal volume of the volume expanding portion 15 can be provided as a space for sufficiently performing heat exchange between the injected refrigerant after passing through the electric motor 13 and the discharged refrigerant from the low stage portion 11, It is possible to sufficiently exchange heat between the injected refrigerant and the refrigerant discharged from the low stage portion 11, so that the temperature and density of both refrigerant groups are equalized to form one refrigerant group and sucked into the high stage portion 12. it can. Further, since the volume expanding portion 15 is composed of a tank having a predetermined capacity, it is possible to obtain the muffler effect of the intermediate pressure refrigerant derived from the refrigerant outlet pipe 22.

For this reason, the density of the refrigerant sucked into the high stage part 12 is stabilized, and the mass flow rate of the refrigerant with the discharge pressure discharged from the high stage part 12 is stabilized, so that the stability of the operation characteristics of the refrigerant circuit device is improved, In addition, it is possible to avoid the occurrence of vibration and noise of the two-stage compressor caused by the unstable discharge mass flow rate. Further, even when there is an injection refrigerant that is liquid without being gasified even after passing through the electric motor 13, the intermediate pressure outside the sealed container 10 that extends from the refrigerant outlet pipe 22 including the volume expansion section 15 to the high stage section 12. In the pipe through which the refrigerant flows, the refrigerant is completely gasified by exchanging heat with the refrigerant discharged from the low stage portion 11, so that a situation in which the liquid refrigerant is sucked into the high stage portion 12 can be avoided. Therefore, a highly efficient and highly reliable compressor 6 is obtained, and a refrigerant circuit device using the compressor 6 is also highly efficient and highly reliable.

Embodiment 3 FIG.
FIG. 4 is an explanatory diagram showing the periphery of an internal intermediate pressure type two-stage compressor 7 (hereinafter referred to as compressor 7) used in the two-stage compression refrigerant circuit device according to Embodiment 3 for carrying out the present invention. . In the compressor 7, the intermediate-pressure refrigerant compressed in the low stage portion 11 is supplied from a first low stage discharge pipe 29 (corresponding to the low stage discharge pipe 21 in FIGS. 2 and 3) that opens into the sealed container 10. What is discharged into the space below the electric motor 13 in the sealed container 10 and the first low-stage discharge pipe 29 are provided separately from the second low-stage discharge pipe 30 connected to the first intermediate pressure connection pipe 27. 10 is diverted to that directly discharged to the first intermediate pressure connecting pipe installed outside. This point is different from the compressors 1 and 6 of the other embodiments shown in FIGS.

In the compressors 1 and 6 of the other embodiments shown in FIGS. 2 and 3, all of the refrigerant discharged from the low stage portion 11 is discharged into the sealed container 10, but the lubricating oil contained in the refrigerant discharged at that time Is separated from the refrigerant in the sealed container 10 and returns to the oil sump 17 at the bottom of the sealed container 10. Since the suction chamber of the low step portion 11 is at a low pressure (suction pressure), the pressure is lower than the intermediate pressure atmosphere in the sealed container 10, so that the lubricating oil can be easily supplied from the oil reservoir 17 due to the pressure difference, and the rotating shaft 14 (not shown). Lubricating oil is supplied to the lower step portion 11 from an oil hole provided in the lower hole portion 11 and is used for lubricating the sliding portion of the lower step portion 11 and sealing the compression chamber.

On the other hand, since there is no portion where the pressure is lower than the intermediate pressure in the airtight container 10 in the high step portion 11, it is difficult to supply the lubricating oil in the oil sump 17. Therefore, a method of supplying lubricating oil used for lubrication and sealing of the high stage portion 12 by mixing the lubricating oil into the intermediate pressure refrigerant sucked into the high stage suction pipe 23 or the high stage portion 12 can be considered. For that purpose, if the refrigerant discharged from the low stage portion 11 is not discharged into the sealed container 10 and is sucked into the high stage portion 12 via a pipe outside the sealed container 10, the refrigerant is supplied to the low stage portion 11. Since a part of the lubricating oil is mixed in the refrigerant discharged from the low stage portion 11, the lubricating oil can be supplied to the high stage portion 12.

When the entire amount of refrigerant discharged from the low stage portion 11 is discharged to the piping outside the sealed container 10 and sucked into the high stage section 12 as it is, the discharged refrigerant gas at the discharge pressure from the high stage section 12 Since it is discharged directly to the connecting pipe A40 outside the sealed container 10 without being opened, the refrigerant and oil are never separated inside the sealed container 10. Therefore, the lubricating oil in the oil sump 17 is gradually taken out of the closed container 10 and eventually causes oil exhaustion, which may cause abnormal wear of the sliding portion and locking of the rotary shaft 14 due to poor lubrication.

In order to avoid such a fear, it is necessary to discharge the refrigerant discharged from the low stage portion 11 also into the sealed container 10, and the refrigerant discharged from the low stage section 11 is discharged into the sealed container 10, This is divided into a pipe that is installed outside the hermetic container 10 and is directly discharged to a pipe through which an intermediate-pressure refrigerant that reaches the high-stage suction pipe 23 flows. The ratio of the diversion is adjusted so that the amount of the lubricating oil supplied to the high step portion 12 does not cause oil exhaustion and is an appropriate amount that can satisfy the lubrication and sealing of the high step portion 12.

As described above, the first intermediate pressure connection pipe 27 of the compressor 7 is connected to the low-stage portion 11 in order to divert the refrigerant discharged from the low-stage portion 11 and suck the intermediate-pressure refrigerant after the diversion into the high-stage portion 12. The connection port A27a connected to the second low-stage discharge pipe 30 through which the refrigerant discharged directly from the outside of the sealed container 10 passes, the refrigerant discharged into the sealed container 10 and the injected refrigerant after passing through the electric motor 13 A connection port B27b connected to the refrigerant outlet tube 22 passing therethrough is provided. Due to the suction action of the high stage portion 12 from these connection ports 27a, 27b, the intermediate pressure refrigerant passes through the first intermediate pressure connection pipe 27, and the volume expanding portion 15, the second intermediate pressure connection pipe 28, and the high stage suction pipe 23. After that, it is sucked into the high step portion 12.

At that time, the lubricating oil mixed in the refrigerant that has passed through the second low-stage discharge pipe 30 is supplied to the high-stage portion 12 together with the refrigerant to lubricate the sliding portion and seal the compression chamber. As a result, the sliding characteristics of the high step portion 12 are improved, the mechanical loss is reduced, and the leakage loss can be reduced by improving the sealing performance of the compression chamber, so that the compressor efficiency is increased. Further, the lubricating oil mixed in the refrigerant that has passed through the first low-stage discharge pipe 29 is separated from the refrigerant in the sealed container 10 and returns to the oil reservoir 17, so that the lubricating oil in the oil reservoir 17 is not exhausted.

4 that are the same as those in FIG. 3 are the same or similar parts as the compressor 6 in FIG. 3, and a description thereof is omitted here. The embodiment of the refrigerant circuit device on which the compressor 7 is mounted is similar to the refrigerant circuit device shown in FIG. 1, and the compressor 1 is changed to the compressor 7 in FIG. Description is omitted. Also in the compressor 7, low-temperature refrigerant reduced from high pressure to intermediate pressure is injected through the injection pipe 26 into the space B 32 in the sealed container 10 of the compressor 7, and due to the latent heat when passing through the electric motor 13. The electric motor 13 is cooled, and the efficiency of the electric motor 13 is increased.

And the structure is such that the refrigerant discharged from the lower stage portion 11 is discharged into the sealed container 10 as in the compressor 7 and the refrigerant discharged directly into the pipe installed outside the sealed container 10. Also, in the pipe through which the intermediate-pressure refrigerant outside the sealed container 10 from the refrigerant outlet pipe 22 including the volume expansion part 15 to the high stage part 12 flows, the refrigerant discharged from each low stage part 11 and the motor 13 after the diversion. Since heat exchange with the injected refrigerant after passing can be sufficiently performed, when sucked into the high stage portion 12, the temperature and density are equalized to form one refrigerant group. The density of the refrigerant to be discharged is stabilized, and the mass flow rate of the refrigerant having the discharge pressure discharged from the high stage portion 12 is stabilized.

Therefore, the stability of the operating characteristics of the refrigerant circuit device can be improved, and the compressor vibration and noise caused by the unstable discharge mass flow rate can be avoided. Further, even when there is an injection refrigerant that is liquid without being gasified even after passing through the electric motor 13, the intermediate pressure outside the sealed container 10 that extends from the refrigerant outlet pipe 22 including the volume expansion section 15 to the high stage section 12. In the pipe through which the refrigerant flows, the refrigerant is completely gasified by exchanging heat with the refrigerant discharged from the low stage portion 11, so that a situation in which the liquid refrigerant is sucked into the high stage portion 12 can be avoided. Further, by dividing the refrigerant discharged from the low step portion 11, oil can be supplied to the high step portion 12, the sliding characteristics and the sealing performance of the high step portion 12 can be improved, and the lubricating oil depletion of the oil reservoir 17 can be avoided. Therefore, the highly efficient and highly reliable compressor 7 is obtained, and the refrigerant circuit device using the compressor 7 is also highly efficient and highly reliable.

Although the compressor 7 was provided with the volume expanding section 15, it did not include the volume expanding section, and as shown in the compressor 1 of FIG. 2, the refrigerant outlet pipe 22 and the high stage suction pipe 23 were connected via the intermediate pressure connecting pipe. Even if it is configured to be connected directly, heat exchange between the refrigerants is performed in a pipe through which the intermediate-pressure refrigerant outside the sealed container 10 from the refrigerant outlet pipe 22 to the high-stage suction pipe 23 flows. Can produce various effects.

In the compressor 7 shown in FIG. 4, connection ports 27 a and 27 b are provided in the first intermediate pressure connection pipe 27, and the refrigerant outlet pipe 22 and the second low-stage discharge pipe 30 are provided in the first intermediate pressure connection pipe 27. However, the second low-stage discharge pipe 30 may be connected to the refrigerant outlet pipe 22. Since the refrigerant outlet pipe 22 and the first intermediate pressure connecting pipe 27 or the refrigerant outlet pipe 22 and the intermediate pressure connecting pipe 25 as shown in FIG. 2 can be collectively determined as the refrigerant outlet pipe, the compression shown in FIG. If the machine 7 also makes such a determination, it can be said that the second low-stage discharge pipe 30 is connected to the refrigerant outlet pipe, and if the volume expansion portion 15 is not provided, the second low-stage is connected to the intermediate pressure connection pipe 25. It can be said that the one connected to the discharge pipe 30 is connected to the second low-stage discharge pipe 30 to the refrigerant outlet pipe.

Further, including the first intermediate pressure connection pipe 27 to the high stage suction pipe 23, or in the form of FIG. 2 that does not include the volume expanding section 15, the intermediate pressure connection pipe 25 and the high stage suction pipe 23 are included in the high stage suction pipe. In this case, when the second low stage discharge pipe 30 is connected to the first intermediate pressure connection pipe 27 or the intermediate pressure connection pipe 25, the second low stage discharge pipe 30 is connected to the high stage suction pipe 23. It can be said that it is connected to a location close to the refrigerant outlet tube 22. The refrigerant discharged from the second low-stage discharge pipe 30 needs to sufficiently exchange heat with the refrigerant discharged from the refrigerant outlet pipe 22 and the refrigerant discharged from the first low-stage discharge pipe. It is preferable to join the injected refrigerant and the refrigerant discharged from the first low-stage discharge pipe at a position away from 12 and as close as possible to the opening to the space A31 of the refrigerant outlet pipe 22.

In the above-described compressors 1, 6, and 7, the low-stage discharge pipe 21 or the first low-stage discharge pipe 29 and the refrigerant outlet pipe 22 have a phase difference of about 180 ° around the axis of the rotating shaft 14. The low-stage discharge pipes 21 and 29 and the refrigerant are arranged so as to cause heat exchange between the refrigerant discharged from the low-stage portion 11 and the injected refrigerant that has passed through the electric motor 13 in the space below the motor 13. In order to increase the distance of the outlet tube 22, it is installed in such a manner. If the intermediate pressure connecting pipes 25 and 27 or the volume expanding section 15 are added so that heat exchange between the two refrigerant groups can be sufficiently performed only outside the sealed container 10, the low-stage discharge pipe 21 or the first low-stage discharge pipe is used. The positional relationship between 29 and the refrigerant outlet tube 22 is not related to the above relationship. Similarly, the positional relationship between the ejection pipe 26 and the refrigerant outlet pipe 22 is not limited to a relation having a phase difference of about 180 ° with the axis of the rotating shaft 14 as the center.

In the refrigerant circuit device shown in FIG. 1, the same applies when any of the compressors 1, 6, 7 is used, but the refrigerant injected from the injection pipe 26 into the sealed container 10 of the compressor 1, 6, 7 is During operation of the apparatus, it is not necessary to always inject, and only when it is determined that injection is necessary, for example, the temperature of the electric motor 13 and the temperature of the refrigerant discharged from the high stage discharge pipe 24 (or the surface of the high stage discharge pipe 24) The temperature may be monitored by a sensor or the like, and injection may be performed when the temperature exceeds a threshold value. When injection is unnecessary, the valve may be closed when a valve mechanism such as an expansion valve is used for the pressure reducing device 5. When a capillary tube is used for the decompression device 5, a switching valve is installed upstream of the capillary tube (in the range of the branch pipe A50), and the switching valve is opened when injection is necessary and closed when unnecessary. You can do it.

Embodiment 4 FIG.
FIG. 5 is a configuration diagram of a two-stage compression refrigerant circuit device according to a fourth embodiment for carrying out the present invention, and is a heat pump type refrigeration air conditioner. 5 that are the same as those in FIG. 1 are the same as or equivalent to those in the refrigerant circuit device of FIG. 1, and a description thereof is omitted here. In the refrigerant circuit device of FIG. 5, the high-pressure and low-temperature refrigerant that has passed through the high-pressure side heat exchanger 2 and exchanged heat with the atmosphere at that time is decompressed to an intermediate pressure by the decompression device 5, and one end is gas-liquid separated. It flows into the gas-liquid separator 8 through the connection pipe E44 that opens to the upper part of the vessel 8 and connects the other end to the decompression device 5. A part of the refrigerant flowing into the gas-liquid separator 8 evaporates there, and inside the gas-liquid separator 8 there is a gas refrigerant layer 8a of the evaporated refrigerant on the upper side, and the bottom part in the gas-liquid separator 8 A liquid refrigerant layer 8b in which liquid refrigerant is stored is divided and formed on the side. Then, only the liquid refrigerant in the liquid layer 8 b flows out to the expansion device 3 through the connection pipe F <b> 45 having one end opened at the bottom of the gas-liquid separator 8 and the other end connected to the expansion device 3.

On the other hand, the gas refrigerant in the gas refrigerant layer 8a is injected into the space B32 in the sealed container 10 of the compressor 1 through the branch pipe 52 having one end opened to the gas refrigerant layer 8a and the other end connected to the injection pipe 26, The electric motor 13 is cooled. Since the subsequent refrigerant flow is the same as that of the refrigerant circuit device of FIG. 1, the description thereof is omitted here. Since the gasified refrigerant is injected into the space B32 in the sealed container 10, the liquid refrigerant can be prevented from being sucked into the high stage 12, and the liquid refrigerant in the gas-liquid separator 8 is evaporated through the expansion device 3. Is evaporated in the low-pressure side heat exchanger 4 that is a condenser, the liquid refrigerant flowing into the expansion device 3 becomes a saturated liquid refrigerant, and has a lower enthalpy than the refrigerant before flowing into the gas-liquid separator 8. There is an effect that can increase the refrigerating capacity.

In the form of the refrigerant circuit device of FIG. 5, since the gas refrigerant is injected into the space B32 of the compressor 1, the latent heat of the refrigerant cannot be used for cooling the motor 13, and the cooling effect on the motor 13 is the same as that of FIG. Compared to the one in which the refrigerant between the outlet of the high-pressure side heat exchanger 2 and the expansion device 3 as shown in the apparatus is branched and the decompressed liquid refrigerant or the gas-liquid two-phase refrigerant is injected into the space B32 in the sealed container 1 However, the liquid refrigerant flowing into the expansion device 3 becomes a saturated liquid refrigerant, and has an effect that the enthalpy is lower than that of the refrigerant before flowing into the gas-liquid separator 8 and the refrigeration capacity in the evaporation step can be increased.

Embodiment 5 FIG.
FIG. 6 is a configuration diagram of a two-stage compression refrigerant circuit device according to Embodiment 5 for carrying out the present invention, and is a heat pump type refrigeration air conditioner. 6 that are the same as those in FIG. 1 or FIG. 5 are the same or similar parts as the refrigerant circuit device of FIG. 1 or FIG. 5, and a description thereof is omitted here. In the refrigerant circuit device of FIG. 6, the decompression device 5 is connected in the middle of the branch pipes 50, 53 with one end connected between the high-pressure side heat exchanger 2 and the expansion device 3 and the other end connected to the injection pipe 26 of the compressor 1. A part of the refrigerant after passing through the high-pressure side heat exchanger 2 flowing through the connecting pipe B41 connecting the outlet of the high-pressure side heat exchanger 2 and the expansion device 3 is branched to the branch pipe A50, The refrigerant circuit device shown in FIG. 6 is the same as the first embodiment shown in FIG. 1 in that the pressure is reduced to the pressure and the refrigerant is injected into the space B32 of the compressor 1 through the branch pipe C53 and the injection pipe 26. A heat exchange part 54 is provided, and the branch pipe C53 and the connection pipe B41 are configured to pass through the heat exchange part 54, respectively. Then, the high-pressure refrigerant flowing through the connecting pipe B41 and the refrigerant flowing through the branch pipe C53 after passing through the decompression device 5 are mutually heat-exchanged, and the branched refrigerant is converted into a gasified or gas-liquid two-phase state. It injects to B32. That is, the heat exchanging section 54 is branched between the high pressure side heat exchanger 2 and the expansion device 3 before injecting a part of the refrigerant branched and decompressed to the intermediate pressure by the decompression device 5 into the space B32 of the compressor 1. Heat exchange with the high-pressure refrigerant flowing through

In the form of the refrigerant circuit device of FIG. 6, since the gas refrigerant or the gas-liquid two-phase refrigerant after heat exchange is injected into the space B <b> 32 of the compressor 1 by the heat exchange unit 54, The latent heat cannot be sufficiently used, and the cooling effect on the electric motor 13 is such that the refrigerant between the outlet of the high-pressure side heat exchanger 2 and the expansion device 3 as shown in the refrigerant circuit device of FIG. Although it is smaller than that in which the liquid two-phase refrigerant is injected into the space B <b> 32 in the sealed container 1, the high-pressure refrigerant flowing between the high-pressure side heat exchanger 2 and the expansion device 3 branches at the heat exchange unit 60. Since the refrigerant flowing through the pipe C53 is deprived of heat, the enthalpy of the refrigerant flowing into the expansion device 3 is lowered, and the refrigeration capacity in the evaporation step can be increased.

In FIG. 6, the heat exchanging section 54 is provided on the upstream side from the point where the branch pipe A50 branches from the connection pipe B41, that is, on the high-pressure side heat exchanger 2 side, and on the upstream side from the point where the branch pipe A50 branches. The refrigerant flowing in the pipe, that is, the refrigerant flowing in the connection pipe B41 and the refrigerant flowing in the branch pipe C53 are exchanged in heat before branching, but the heat exchange part 54 is located downstream from the point where the branch pipe A50 branches from the connection pipe B41. That is, heat is exchanged between the refrigerant that flows through the connecting pipe B41 downstream from the point where the branch pipe A50 branches, that is, the refrigerant that flows through the connecting pipe B41 after branching and the refrigerant that flows through the branch pipe C53. However, the same effect can be obtained.

In the refrigeration circuit device shown in FIGS. 5 and 6, the compressor 1 shown in the first embodiment is used as the compressor, but the compressors 6 and 7 shown in the other embodiments may be used. . In each of the compressors 1, 6, and 7 used in the refrigerant circuit device of FIG. 1, FIG. 5, or FIG. 6, the ratio of the stroke volume of the low stage portion 11 to the stroke volume of the high stage portion 12 is high. In addition to the refrigerant discharged from the low-stage part 11 in the part 12, the refrigerant injected into the sealed container 10 from the injection pipe 26 is also sucked, so that compared to a general two-stage compressor not provided with an injection pipe If the stroke volume of the high step portion 12 is set slightly larger and the stroke volume of the low step portion 11 is 1, the stroke volume of the high step portion 12 is set to 0.6 to 0.85.

In the refrigerant circuit device shown in FIG. 6, the same applies when any of the compressors 1, 6, and 7 is used, but the refrigerant that is injected from the injection pipe 26 into the sealed container 10 of the compressors 1, 6, and 7 is During operation of the apparatus, it is not necessary to always inject, and only when it is determined that injection is necessary, for example, the temperature of the electric motor 13 and the temperature of the refrigerant discharged from the high stage discharge pipe 24 (or the surface of the high stage discharge pipe 24) The temperature may be monitored by a sensor or the like, and injection may be performed when the temperature exceeds a threshold value. When injection is unnecessary, the valve may be closed when a valve mechanism such as an expansion valve is used for the pressure reducing device 5. When a capillary tube is used for the decompression device 5, a switching valve is installed upstream of the capillary tube (in the range of the branch pipe A50), and the switching valve is opened when injection is necessary and closed when unnecessary. You can do it.

The refrigerant circuit device shown in FIG. 1 is a heat pump type hot water supply device using carbon dioxide as a refrigerant. However, the refrigerant circuit device may be applied to a refrigeration air conditioner as shown in FIG. 5 or FIG. Well, it can be said that carbon dioxide is suitable as a refrigerant for hot water supply, but it is not limited to this, and in particular for refrigeration and air conditioning, HFC refrigerant and HC refrigerant can be applied other than carbon dioxide, and the same effect is exhibited. be able to. Also, the refrigerant circuit device shown in FIGS. 5 and 6 may be applied to a hot water supply application, and carbon dioxide is appropriate if the refrigerant to be used is also for hot water supply. HFC refrigerant and HC refrigerant can be applied, and similar effects can be achieved.

It is a block diagram of the refrigerant circuit apparatus which shows Embodiment 1 of this invention. It is explanatory drawing which shows the compressor periphery which shows Embodiment 1 of this invention. It is explanatory drawing which shows the compressor periphery which shows Embodiment 2 of this invention. It is explanatory drawing which shows the compressor periphery which shows Embodiment 3 of this invention. It is a block diagram of the refrigerant circuit apparatus which shows Embodiment 4 of this invention. It is a block diagram of the refrigerant circuit apparatus which shows Embodiment 5 of this invention.

Explanation of symbols

  1, 6, 7 compressor, 2 high pressure side heat exchanger, 3 expansion device, 4 low pressure side heat exchanger, 5 decompression device, 8 gas-liquid separator, 8a gas refrigerant layer, 8b liquid refrigerant layer, 10 sealed container, 10a Cylindrical container, 10b Upper lid, 10c Bottom lid, 11 Low stage compression mechanism (low stage), 12 High stage compression mechanism (high stage), 13 Electric motor, 13a Stator, 13b Rotor, 14 rotations Shaft, 15 volume expansion section, 16 receptacle, 17 oil sump, 20 low stage suction pipe, 21 low stage discharge pipe, 22 refrigerant outlet pipe, 23 high stage suction pipe, 24 high stage discharge pipe, 25 intermediate pressure connection pipe, 26 injection pipe, 27 first intermediate pressure connection pipe, 28 second intermediate pressure connection pipe, 29 first low stage discharge pipe, 30 second low stage discharge pipe, 31 space A, 32 space B, 40 connection pipe A, 41 Connection piping B, 42 Connection piping C, 43 Connection piping D, 4 4 connection pipe E, 45 connection pipe F, 50 branch pipe A, 51 branch pipe B, 52 branch pipe, 53 branch pipe C, 54 heat exchanger, 60 hot water storage tank, 61 pump, 62 water pipe.

Claims (7)

A hermetically sealed container that houses therein an electric motor and a compression mechanism unit composed of a low-stage compression mechanism unit and a high-stage compression mechanism unit driven by a rotating shaft coupled to the electric motor;
One end of the motor on the anti-compression mechanism part side of the electric motor and the sealed container is opened at one end, and an injection pipe for injecting refrigerant into the sealed container from the outside of the sealed container;
A low-stage discharge pipe for discharging the refrigerant compressed by the low-stage compression mechanism into the sealed container;
A refrigerant outlet pipe that opens at one end to a space between the electric motor and the compression mechanism, and leads the refrigerant injected from the injection pipe and the refrigerant discharged from the low-stage discharge pipe to the outside of the sealed container; ,
A high-stage suction pipe connected to the other end of the refrigerant lead-out pipe and sucking the refrigerant led out from the refrigerant lead-out pipe into the high-stage compression mechanism;
The compressor characterized by having. 2. The compressor according to claim 1, further comprising a volume expansion portion having an inner diameter larger than an inner diameter of the refrigerant outlet pipe and the higher stage suction pipe between the refrigerant outlet pipe and the higher stage suction pipe. . A portion of the refrigerant outlet pipe or the high stage suction pipe adjacent to the refrigerant outlet pipe is connected to the outside of the airtight container, and the refrigerant is discharged from the low stage discharge pipe into the airtight container to be diverted to the low airflow. The second low-stage discharge pipe that guides the refrigerant compressed by the stage-side compression mechanism section from the low-stage compression mechanism section to the high-stage compression mechanism section. Compressor. The said refrigerant | coolant derivation | leading-out pipe | tube is provided in the direction substantially 180 degrees symmetrical with the direction where the said low stage discharge pipe | tube is located centering | focusing on the axial center of the said rotating shaft. The compressor described. In the sealed container, an electric motor and a compression mechanism unit composed of a low-stage compression mechanism unit and a high-stage compression mechanism unit driven by a rotating shaft connected to the electric motor are housed, and the low-stage compression mechanism unit A low-pressure refrigerant is sucked into the compressor and a high-pressure refrigerant discharged from the compressor exchanges heat with a compressor that discharges a high-pressure refrigerant that is sequentially compressed by the low-stage compression mechanism and the high-stage compression mechanism. Sequentially connecting a high-pressure side heat exchanger to be performed, a throttle device that depressurizes the refrigerant after passing through the high-pressure side heat exchanger to a low pressure, and a low-pressure side heat exchanger that performs heat exchange with the low-pressure refrigerant after passing through the throttle device A refrigerant circuit for circulating the refrigerant,
One end connected between the high-pressure side heat exchanger and the expansion device, a branch pipe provided with a decompression device in the middle,
Refrigerant after one end is opened in the space between the electric motor and the sealed container on the side of the anti-compression mechanism of the electric motor, the other end is connected to the other end of the branch pipe, and passes through the high-pressure side heat exchanger An injection pipe of the compressor that injects the refrigerant that has passed through the branch pipe at a part thereof and has been decompressed by the decompression device into the sealed container;
A low-stage discharge pipe of the compressor that discharges the refrigerant compressed by the low-stage compression mechanism into the sealed container;
One end of the compressor is opened to a space between the electric motor and the compression mechanism, and the refrigerant injected from the injection pipe and the refrigerant discharged from the low-stage discharge pipe are led out of the sealed container. A refrigerant outlet tube;
A high-stage suction pipe of the compressor that is connected to the other end of the refrigerant lead-out pipe and sucks the refrigerant led out from the refrigerant lead-out pipe into the high-stage compression mechanism;
A refrigerant circuit device comprising: In the sealed container, an electric motor and a compression mechanism unit composed of a low-stage compression mechanism unit and a high-stage compression mechanism unit driven by a rotating shaft connected to the electric motor are housed, and the low-stage compression mechanism unit A low-pressure refrigerant is sucked into the compressor and a high-pressure refrigerant discharged from the compressor exchanges heat with a compressor that discharges a high-pressure refrigerant that is sequentially compressed by the low-stage compression mechanism and the high-stage compression mechanism. Sequentially connecting a high-pressure side heat exchanger to be performed, a throttle device that depressurizes the refrigerant after passing through the high-pressure side heat exchanger to a low pressure, and a low-pressure side heat exchanger that performs heat exchange with the low-pressure refrigerant after passing through the throttle device A refrigerant circuit for circulating the refrigerant,
A decompression device for decompressing the refrigerant after passing through the high pressure side heat exchanger between the high pressure side heat exchanger and the expansion device;
A gas-liquid separator formed between the high-pressure side heat exchanger and the expansion device, the refrigerant decompressed by the decompression device flows therein, and a liquid refrigerant layer and a gas refrigerant layer are formed inside;
A branch pipe having one end opened in the gas refrigerant layer of the gas-liquid separator;
One end is opened in the space between the motor on the anti-compression mechanism part side of the motor and the sealed container, the other end is connected to the other end of the branch pipe, and the gas-liquid separator that has passed through the branch pipe An injection pipe of the compressor for injecting a refrigerant of a gas refrigerant layer into the sealed container;
A low-stage discharge pipe of the compressor that discharges the refrigerant compressed by the low-stage compression mechanism into the sealed container;
One end of the compressor is opened to a space between the electric motor and the compression mechanism, and the refrigerant injected from the injection pipe and the refrigerant discharged from the low-stage discharge pipe are led out of the sealed container. A refrigerant outlet tube;
A high-stage suction pipe of the compressor that is connected to the other end of the refrigerant lead-out pipe and sucks the refrigerant led out from the refrigerant lead-out pipe into the high-stage compression mechanism;
A refrigerant circuit device comprising: In the sealed container, an electric motor and a compression mechanism unit composed of a low-stage compression mechanism unit and a high-stage compression mechanism unit driven by a rotating shaft connected to the electric motor are housed, and the low-stage compression mechanism unit A low-pressure refrigerant is sucked into the compressor and a high-pressure refrigerant discharged from the compressor exchanges heat with a compressor that discharges a high-pressure refrigerant that is sequentially compressed by the low-stage compression mechanism and the high-stage compression mechanism. Sequentially connecting a high-pressure side heat exchanger to be performed, a throttle device that depressurizes the refrigerant after passing through the high-pressure side heat exchanger to a low pressure, and a low-pressure side heat exchanger that performs heat exchange with the low-pressure refrigerant after passing through the throttle device A refrigerant circuit for circulating the refrigerant,
One end connected between the high-pressure side heat exchanger and the expansion device, a branch pipe provided with a decompression device in the middle,
A heat exchanging section for exchanging heat between the refrigerant flowing through the branch pipe after passing through the decompression device and the refrigerant flowing between the high-pressure side heat exchanger and the expansion device;
Refrigerant after one end is opened in the space between the electric motor and the sealed container on the side of the anti-compression mechanism of the electric motor, the other end is connected to the other end of the branch pipe, and passes through the high-pressure side heat exchanger An injection pipe of the compressor that passes through the branch pipe in a part of the compressor and depressurizes by the decompression device, and injects the refrigerant heat-exchanged by the heat exchange unit into the sealed container;
A low-stage discharge pipe of the compressor that discharges the refrigerant compressed by the low-stage compression mechanism into the sealed container;
One end of the compressor is opened to a space between the electric motor and the compression mechanism, and the refrigerant injected from the injection pipe and the refrigerant discharged from the low-stage discharge pipe are led out of the sealed container. A refrigerant outlet tube;
A high-stage suction pipe of the compressor that is connected to the other end of the refrigerant lead-out pipe and sucks the refrigerant led out from the refrigerant lead-out pipe into the high-stage compression mechanism;
A refrigerant circuit device comprising:

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