JP6943345B2 - Multi-stage compressor - Google Patents

Description

The present invention has a multi-stage compression mechanism, and even if the amount of refrigerant circulation introduced into the low-stage compression mechanism and the amount of refrigerant circulation introduced into the high-stage compression mechanism are different, the apparatus has a simple configuration. It relates to a multi-stage compressor that can realize the miniaturization of.

Conventionally, there is one in which a two-stage compression mechanism is provided in one scroll compressor. For example, in Patent Document 1, a land portion for dividing a fixed scroll compression chamber into two stages is provided, and a low-stage compression mechanism on the outer peripheral side and a high-stage compression mechanism on the inner peripheral side are divided by the land portion. A two-stage compression scroll compressor is described in which the air compressed by the low-stage compression mechanism is introduced into the high-stage compression mechanism.

Japanese Unexamined Patent Publication No. 2004-332556

By the way, in the above-mentioned two-stage compression scroll compressor, the amount of refrigerant circulation compressed by the low-stage compression mechanism is directly compressed by the high-stage compression mechanism. Here, when applying a two-stage compression scroll compressor to a two-stage compression two-stage expansion cycle compressor, an intermediate-pressure refrigerant expanded by a high-stage expansion valve is introduced into the high-stage compression mechanism. Therefore, the amount of refrigerant circulation introduced into the high-stage compression mechanism is larger than the amount of refrigerant circulation introduced into the low-stage compression mechanism, and it is difficult to realize two-stage compression. In order to realize this two-stage compression two-stage expansion cycle, a pair of scroll compressors including a low-stage scroll compressor and a high-stage scroll compressor was required. For this reason, in the scroll compressor of the two-stage compression two-stage expansion cycle, the apparatus configuration has become large and the piping configuration has become complicated.

The present invention has been made in view of the above, and an object of the present invention is to provide a multi-stage compressor capable of consolidating a large number of valves, openings, and pipes peculiar to two-stage compression to achieve maintainability and compactness. And.

In order to solve the above-mentioned problems and achieve the object, the multi-stage compressor according to the present invention uses a plurality of compression chambers provided in the housing and an intermediate pressure refrigerant from the lower-stage compression chambers of the plurality of compression chambers. An intermediate pressure refrigerant discharge port to be discharged, an intermediate pressure refrigerant suction port that opens in the same direction as the intermediate pressure refrigerant discharge port and sucks the intermediate pressure refrigerant into the higher stage side of the plurality of compression chambers, and the intermediate pressure refrigerant. A high-pressure refrigerant discharge port that opens in the same direction as the discharge port and discharges high-pressure refrigerant discharged from the high-stage side compression chambers of the plurality of compression chambers, and an intermediate pressure refrigerant suction port that is detachably attached to the housing. An intermediate pressure refrigerant chamber having an external intermediate pressure refrigerant connection introduction port that communicates with the intermediate pressure refrigerant discharge port and opens to the outside, and a high pressure refrigerant outlet that communicates with the high pressure refrigerant discharge port and opens to the outside. It is characterized by including a high-pressure refrigerant chamber and a refrigerant connection cover forming the refrigerant chamber.

Further, in the above invention, the multi-stage compressor according to the present invention has a housing that opens in the same direction as the intermediate pressure refrigerant discharge port and discharges the intermediate pressure refrigerant through a seal in the housing. A body intermediate pressure refrigerant suction port is formed, and the intermediate pressure refrigerant suction port and the external intermediate pressure refrigerant connection introduction port are connected by a pipe.

Further, in the above invention, the multi-stage compressor according to the present invention communicates the high-stage side compression chamber with the high-pressure refrigerant chamber when the internal pressure of the high-stage side compression chamber becomes equal to or higher than a predetermined value. The high-pressure relief means is provided in the high-pressure refrigerant chamber of the housing.

Further, in the above invention, the multi-stage compressor according to the present invention communicates the low-stage side compression chamber with the intermediate pressure refrigerant chamber when the internal pressure of the low-stage side compression chamber becomes equal to or higher than a predetermined value. It is characterized in that the intermediate pressure relief means for causing the intermediate pressure is provided in the intermediate pressure refrigerant chamber of the housing.

Further, in the multi-stage compressor according to the present invention, in the above invention, a check valve for preventing backflow from the intermediate pressure refrigerant discharge port to the compression chamber is provided in the intermediate pressure refrigerant chamber of the housing. It is characterized by being.

Further, in the multi-stage compressor according to the present invention, in the above invention, a check valve for preventing backflow from the high-pressure refrigerant discharge port to the compression chamber is provided in the high-pressure refrigerant chamber of the housing. It is characterized by that.

Further, in the above-mentioned invention, the multi-stage compressor according to the present invention is a scroll compressor including a swivel scroll and a fixed scroll, and the fixed scroll constitutes a part of the housing. It is characterized in that the refrigerant connection cover is attached.

Further, the multi-stage compressor according to the present invention is characterized in that, in the above invention, the volume of the intermediate pressure refrigerant chamber is made larger than the volume of the high pressure refrigerant chamber.

Further, the multi-stage compressor according to the present invention is characterized in that, in the above invention, the refrigerant connection cover is provided with a notch for positioning.

Further, the multi-stage compressor according to the present invention is characterized in that the multi-stage compressor according to any one of the above inventions is used in a thermal cycle system of two-stage compression and two-stage expansion.

According to the present invention, a large number of valves, openings, and pipes peculiar to two-stage compression can be integrated to improve maintainability and compactness.

FIG. 1 is a circuit diagram showing an outline configuration of a thermodynamic cycle system to which a scroll compressor as a multi-stage compressor according to the first embodiment of the present invention is applied. FIG. 2 is a PH diagram of the thermodynamic cycle system shown in FIG. FIG. 3 is a cross-sectional view showing the structure of the scroll compressor. FIG. 4 is a cross-sectional view taken along the line AA shown in FIG. FIG. 5 is a cross-sectional view of the fixed scroll and the swivel scroll shown in FIG. FIG. 6 is a perspective view of the fixed scroll shown in FIG. 4 as viewed from diagonally below. FIG. 7 is a perspective view of the swivel scroll shown in FIG. 4 as viewed from diagonally above. FIG. 8 is an explanatory diagram illustrating a compression operation of the symmetric scroll compressor. FIG. 9 is an explanatory diagram illustrating a compression operation of the asymmetric scroll compressor. FIG. 10 is an explanatory diagram showing the relationship between the position on the involute curve and the involute angle. FIG. 11 is a diagram comparing the compression operations of the symmetric scroll compressor and the asymmetric scroll compressor. FIG. 12 is an explanatory diagram illustrating reduction of recompression loss by the compression operation of the asymmetric scroll compressor. FIG. 13 is a cross-sectional view showing a state when the swivel scroll is tilted. FIG. 14 is an explanatory diagram illustrating a decrease in compression efficiency of the outer compression portion in the state of FIG. 13. FIG. 15 is an explanatory diagram illustrating a decrease in volumetric efficiency of the inner compression portion in the state of FIG. FIG. 16 is a cross-sectional view showing a state in which the ring-shaped seal is provided on the tip surface of the outer wall of the fixed scroll. FIG. 17 is a cross-sectional view taken along the line BB when the scroll compressor shown in FIG. 3 is provided with a ring-shaped seal. FIG. 18 is a cross-sectional view showing a state in which the ring-shaped seal is provided on the base plate of the swivel scroll. FIG. 19 is a diagram showing an example in which a split gap is provided in the ring-shaped seal. FIG. 20 is a diagram showing an example in which a split gap is provided in the ring-shaped seal. FIG. 21 is a diagram showing an example in which a space portion is provided in the ring-shaped seal. FIG. 22 is a circuit diagram showing an example of a thermodynamic cycle system. FIG. 23 is a PH diagram of the thermodynamic cycle system shown in FIG. FIG. 24 is a circuit diagram showing an example of a thermodynamic cycle system. FIG. 25 is a PH diagram of the thermodynamic cycle system shown in FIG. 24. FIG. 26 is a circuit diagram showing an example of a thermodynamic cycle system. FIG. 27 is a PH diagram of the thermodynamic cycle system shown in FIG. FIG. 28 is a circuit diagram showing an example of a thermodynamic cycle system. FIG. 29 is a PH diagram of the thermodynamic cycle system shown in FIG. 28. FIG. 30 is a vertical cross-sectional view showing the configuration of the scroll compressor according to the fourth embodiment. FIG. 31 is a perspective view of the scroll compressor shown in FIG. 30 as viewed diagonally from the right. FIG. 32 is a perspective view of the scroll compressor shown in FIG. 30 as viewed diagonally from the left. FIG. 33 is a perspective view of the refrigerant connection cover shown in FIG. 30 as viewed from the back surface side. FIG. 34 is a front view with the refrigerant connection cover attached. FIG. 35 is a front view with the refrigerant connection cover removed.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

[Embodiment 1]
(Overview of applicable system)
FIG. 1 is a circuit diagram showing an outline configuration of a thermodynamic cycle system 1 to which a scroll compressor 2 as a multi-stage compressor according to the first embodiment of the present invention is applied. Further, FIG. 2 is a PH diagram of the thermodynamic cycle system 1 shown in FIG. Further, the scroll compressor 2 is a two-stage compressor, which is an example of a multi-stage compressor. Further, the thermal cycle of the thermal cycle system 1 is a two-stage compression two-stage expansion cycle.

The high-stage compression chamber of the scroll compressor 2 generates a high-pressure refrigerant RH having a refrigerant circulation amount GH and introduces it into the condenser 3 (points P2 to P3 in FIG. 2). The high-pressure refrigerant RH is radiated and condensed by the condenser 3, and further supercooled by the supercooler 4 (points P3 to P4 in FIG. 2). After that, the high-pressure refrigerant RH is decompressed and expanded by the high-stage expansion valve 5 (points P4 to P5 in FIG. 2) to become an intermediate-pressure refrigerant RM, which is introduced into the gas-liquid separator 6. The gas-state intermediate-pressure refrigerant RM1 which is steam of the intermediate-pressure refrigerant RM is introduced into the high-stage compression chamber of the scroll compressor 2 (point P2 in FIG. 2). On the other hand, the liquid intermediate pressure refrigerant RM2 of the intermediate pressure refrigerant RM is decompressed and expanded by the low stage expansion valve 7 (points P6 to P7 in FIG. 2) to become a low pressure refrigerant RL and is introduced into the evaporator 8. NS. The evaporator 8 evaporates the low-pressure refrigerant RL (points P7 to P1 in FIG. 2) and is introduced into the lower compression chamber of the scroll compressor 2 (point P1 in FIG. 2).

After that, the low-stage compression chamber of the scroll compressor 2 compresses the introduced low-pressure refrigerant RL to the intermediate-pressure refrigerant RM3. The high-stage compression chamber of the scroll compressor 2 compresses the intermediate pressure refrigerants RM1 and RM3 to the high pressure refrigerant RH. Therefore, the liquid refrigerant circulation amount GL separated by the gas-liquid separator 6 is introduced into the lower compression chamber of the scroll compressor 2. On the other hand, in the high-stage compression chamber of the scroll compressor 2, the refrigerant circulation amount GM in the gaseous state separated by the gas-liquid separator 6 and the refrigerant circulation amount GL introduced from the low-stage compression chamber are added. The refrigerant circulation amount GH is introduced. That is, the amount of refrigerant circulation introduced into the high-stage compression chamber is larger than the amount of refrigerant circulation introduced into the low-stage compression chamber.

(Scroll compressor)
FIG. 3 is a cross-sectional view showing the structure of the scroll compressor 2. Further, FIG. 4 is a cross-sectional view taken along the line AA shown in FIG. Further, FIG. 5 is a cross-sectional view of the fixed scroll 11 and the swivel scroll 12 shown in FIG. Further, FIG. 6 is a perspective view of the fixed scroll 11 shown in FIG. 4 as viewed from diagonally below. Further, FIG. 7 is a perspective view of the swivel scroll 12 shown in FIG. 4 as viewed from diagonally above.

The fixed scroll 11 and the swivel scroll 12 form a later-described outer compression unit 40 that functions as a low-pressure side compression chamber and a later-described inner compression unit 41 that functions as a high-pressure side compression chamber to perform two-stage compression. As shown in FIG. 3, the fixed scroll 11 and the swivel scroll 12 are provided in the housing 10 formed by the housings 10a and 10b. The two-stage compression is performed by the swivel scroll 12 revolving with respect to the fixed scroll 11 in the rotation direction AL. The crankshaft 13 transmits a rotational force from a rotational drive source (not shown) to the rotary scroll 12. The thrust bearing 14 pivotally supports the rotation of the swivel scroll 12 in the thrust direction. An intermediate pressure chamber 16 and a high pressure chamber 17 are formed in the housing 10. The crankshaft 13 is provided with a balance weight 15 for balancing the rotation of the swivel scroll 12 with respect to the revolutionary motion.

The low-pressure refrigerant suction pipe L1 is a pipe that introduces the low-pressure refrigerant RL into the outer compression unit 40. The intermediate pressure refrigerant suction pipe L2 is a pipe for introducing the intermediate pressure refrigerant RM1 into the intermediate pressure chamber 16. The high-pressure refrigerant discharge pipe L3 is a pipe that discharges the high-pressure refrigerant RH discharged from the inner compression unit 41 through the discharge valve 18 and the high-pressure chamber 17 to the outside of the housing 10.

(Two-stage compression mechanism)
As shown in FIGS. 4 to 7, the fixed scroll 11 has fixed scroll plate-shaped spiral teeth 11b erected on the base plate 11a. The swivel scroll 12 has swirl scroll plate-shaped spiral teeth 12b erected on the base plate 12a. The fixed scroll 11 and the swivel scroll 12 mesh the tip of the fixed scroll plate-shaped spiral tooth 11b and the tip of the swirl scroll plate-shaped spiral tooth 12b with each other to form an outer compression portion 40 and an inner compression portion 41. Then, in the outer compression unit 40 and the inner compression unit 41, compression chambers are formed on the outside and inside of the swirl scroll 12, and the swirl scroll 12 revolves to reduce the volume of the compression chamber so that the compression chamber is on the center side. To compress the refrigerant in the compression chamber.

As shown in FIG. 4, between the fixed scroll plate-shaped spiral teeth 11b adjacent to each other so as to divide the compression chamber between the winding start position PA on the center side of the fixed scroll plate-shaped spiral tooth 11b and the outer winding end position PB. A dividing wall 20 is provided. Further, the swivel scroll plate-shaped spiral tooth 12b is formed with a split region E (see FIG. 7) at a position corresponding to the split wall 20 so as not to interfere with the split wall 20 due to the revolving motion of the swivel scroll 12. .. The outer compression portion 40 and the inner compression portion 41 are formed by the dividing wall 20. Further, as shown in FIGS. 5 to 7, the swirl scroll plate-shaped spiral tooth 12b revolves in the outer compression portion 40 due to the formation of the divided region E, and the swirl scroll plate-shaped spiral tooth 32 and the inner compression portion 41 revolve in the outer compression portion 40. It will have a swirl scroll plate-shaped spiral tooth 33 that revolves around. Further, the fixed scroll plate-shaped spiral tooth 11b has a fixed scroll plate-shaped spiral tooth 30 forming the outer compression portion 40 by the dividing wall 20 and a fixed scroll plate-shaped spiral tooth 31 forming the inner compression portion 41. ..

A low-pressure refrigerant suction port 21 is formed at the outer winding end position of the swirl scroll plate-shaped spiral tooth 32 in the outer compression portion 40, and is connected to the low-pressure refrigerant suction pipe L1. Further, at the winding start position of the swirl scroll plate-shaped spiral tooth 32 in the outer compression unit 40, an intermediate pressure refrigerant discharge port 23 for discharging the intermediate pressure refrigerant RM3 compressed in the outer compression unit 40 into the intermediate pressure chamber 16 is formed. NS. Further, an intermediate pressure refrigerant suction port 22 is formed at the outer winding end position of the swirl scroll plate-shaped spiral tooth 33 in the inner compression portion 41 to suck the intermediate pressure refrigerants RM1 and RM3 through the intermediate pressure chamber 16. Further, a high-pressure refrigerant discharge port 24 is formed at the winding start position, that is, at the center of the swirl scroll plate-shaped spiral tooth 33 in the inner compression portion 41. The high-pressure refrigerant discharge port 24 communicates with the high-pressure chamber 17 via the discharge valve 18, and discharges the high-pressure refrigerant RH compressed by the inner compression unit 41 to the outside via the high-pressure refrigerant discharge pipe L3.

Here, since the amount of refrigerant circulation sucked into the inner compression portion 41 is larger than the amount of refrigerant circulation sucked into the outer compression portion 40, as shown in FIG. 5, the fixed scroll plate-shaped spiral teeth forming the inner compression portion 41 are formed. The height h2 of 31 and the swirl scroll plate-shaped spiral tooth 33 is made higher than the height h1 of the fixed scroll plate-shaped spiral tooth 30 and the swirl scroll plate-shaped spiral tooth 32 forming the outer compression portion 40. By adjusting the heights h1 and h2, the compression volume of the inner compression unit 41 can be made larger than the compression volume of the outer compression unit 40. As a result, the intermediate pressure refrigerant expanded by the high-stage expansion valve is introduced into the high-stage compression mechanism, and the amount of refrigerant circulation introduced into the high-stage compression mechanism is larger than the amount of refrigerant circulation introduced into the low-stage compression mechanism. Even so, the device can be downsized with a simple configuration.

As shown in FIG. 5, tip seals 51 and 52 are provided on the tip side of the fixed scroll plate-shaped spiral tooth 11b and the tip side of the swirl scroll plate-shaped spiral tooth 12b, respectively, and the outer compression portion 40 and the above-mentioned outer compression portion 40 and the above-mentioned outer compression portion 40 and During compression by the inner compression portion 41, refrigerant leakage between the outside and the inside of the fixed scroll plate-shaped spiral tooth 11b and refrigerant leakage between the outside and the inside of the swirl scroll plate-shaped spiral tooth 12b are prevented.

[Embodiment 2]
(Application of asymmetric scroll compressor structure)
By the way, as shown in FIG. 8, in the scroll compressor 2 of the second embodiment, the winding end position PB10 of the fixed scroll 11 and the winding end position PB11 of the swivel scroll 12 are centered (the position of the high-pressure refrigerant discharge port 24). It is arranged symmetrically with respect to.

Therefore, as shown in FIG. 8A, in the outer compression unit 40, the low-pressure refrigerant RL first receives the first inner compression chamber 60-1 inside the swirl scroll 12 and the first outer outer side of the swirl scroll 12. It forms a compression chamber 61-1. On the other hand, after one rotation (360 °) of the swivel scroll 12, the first inner compression chamber 60-1 becomes the compressed second inner compression chamber 60-2, and the first outer compression chamber 61-1 becomes the compressed first. 2 The outer compression chamber 61-2. That is, the first inner compression chamber 60-1 and the first outer compression chamber 61-1 show the states before one rotation of the second inner compression chamber 60-2 and the second outer compression chamber 61-2, respectively.

FIG. 8B shows a state in which the swivel scroll 12 is rotated by the communication angle θA in which the second inner compression chamber 60-2 communicates with the intermediate pressure refrigerant discharge port 23 from the state of FIG. 8A. In this case, the intermediate pressure refrigerant in the second inner compression chamber 60-2 communicates with the intermediate pressure refrigerant discharge port 23 and is discharged, and at the same time, communicates with the first outer compression chamber 61-1 and is the first as shown by arrow A1. The compressed intermediate pressure refrigerant in the second inner compression chamber 60-2, which has a relatively higher pressure than the outer compression chamber 61-1, leaks into the first outer compression chamber 61-1. As a result, recompression loss occurs and the compression efficiency decreases.

Therefore, as shown in FIG. 9, it is preferable that the winding end position PB20 of the fixed scroll 11 and the winding end position PB21 of the swivel scroll 12 are arranged asymmetrically with respect to the center (the position of the high-pressure refrigerant discharge port 24). Here, as shown in FIG. 9, the asymmetric scroll compressor sets the winding end position PB10 of the fixed scroll 11 in the symmetric scroll compressor and the extension angle θa from the winding end position PB10 to 0 ° <θa ≦ 180. It is stretched at °. In FIG. 9, the winding end position PB20 is set so that the extension angle θa is 180 °.

Here, each inner wall and each outer wall of the fixed scroll 11 and the swivel scroll 12 form an involute curve LI. The involute curve LI is a plane curve whose normal is always in contact with a constant circle (base circle C). As shown in FIG. 10, where the involute angle of the involute curve LI is θ (°) and the radius of the base circle C is R, the position PB (θ) = {PBx (θ), PBy (θ) on the involute curve L1. )} Can be expressed by the following equation.
PBx (θ) = R {cosθ + (θ × π / 180) sinθ}
PBy (θ) = R {sinθ− (θ × π / 180) cosθ}
Therefore, the above-mentioned extension angle θa is θa = θ2-θ1 when the extension angle of the winding end position PB10 is θ1 and the extension angle of the winding end position PB20 is θ2. In other words, the winding end position PB20 is extended from the winding end position PB10 by the amount corresponding to the extension angle θa.

FIG. 9 shows asymmetric scroll compression in which the winding end position PB20 of the fixed scroll 11 and the winding end position PB21 of the turning scroll 12 are arranged at the same angle position with respect to the symmetric scroll compressor shown in FIG. 8A. It was an opportunity. In this arrangement of the asymmetric scroll compressor, when the first inner compression chamber 60-1 and the first outer compression chamber 61-1 shown in FIG. 8A are formed, the outer compression chamber 61 before half a turn is formed. −0 has already been formed. The outer compression chamber 61-0 becomes the first outer compression chamber 61-1 after one rotation. That is, when the first inner compression chamber 60-1 is formed, the first outer compression chamber 61-1 is already compressed from half a cycle before. Therefore, when the communication angle θA shown in FIG. 8B is obtained, the pressure in the first outer compression chamber 61-1 is substantially the same as the pressure in the second inner compression chamber 60-2, and the second inner compression chamber is compressed. The amount of the intermediate pressure refrigerant compressed in the chamber 60-2 leaking to the first outer compression chamber 61-1 is reduced. As a result, the recompression loss becomes small, and it is possible to prevent a decrease in compression efficiency.

FIG. 11 is a diagram comparing the pressure changes in the inner compression chamber and the outer compression chamber and the pressure difference at the communication angle θA between the symmetric scroll compressor shown in FIG. 8 and the asymmetric scroll compressor shown in FIG. be. The characteristic curves L60-1, L60-2, L61-0, L61-1, and L61-2 are the first inner compression chamber 60-1, the second inner compression chamber 60-2, the outer compression chamber 61-0, and the first, respectively. The pressure changes of 1 outer compression chamber 61-1 and 2nd outer compression chamber 61-2 are shown. As shown in FIG. 11B, in the asymmetric scroll compressor, the outer compression chamber 61- becomes the first outer compression chamber 61-1 from the time of the rotation angle θ1 one rotation before the rotation angle becomes 0 °. Since 0 is compressed, the pressure at the beginning (rotation angle 0 °) of the first outer compression chamber 61-1 is raised to a higher level, and the pressure difference PR2 at the communication angle θA is shown in FIG. 11 (a). The pressure difference is ΔPR smaller than the pressure difference PR1 of the symmetrical scroll compressor shown in 1.

As a result, as shown in FIG. 12, the recompression loss S2 of the asymmetric scroll compressor is smaller than the repressure loss S1 of the symmetric scroll compressor.

The configuration of the asymmetric scroll compressor can be applied not only to the two-stage compression two-stage expansion cycle shown in the first embodiment but also to the two-stage compression one-stage expansion cycle. Specifically, the height h2 of the fixed scroll plate-shaped spiral tooth 31 and the swirl scroll plate-shaped spiral tooth 33 forming the inner compression portion 41 is set to the height h2 of the fixed scroll plate-shaped spiral tooth 30 and the swirl scroll forming the outer compression portion 40. It is not necessary to adopt a configuration in which the height of the plate-shaped spiral tooth 32 is higher than h1.

[Embodiment 3]
(Refrigerant leakage prevention mechanism)
By the way, in the housing 10, the intermediate pressure chamber 16 has an intermediate pressure PM. When the pressure inside the housing 10 is set to the intermediate pressure PM, the intermediate pressure PM is applied to the back surface of the swivel scroll 12, so that the thrust load of the swivel scroll 12 is reduced, the mechanical loss is reduced, and the thrust bearing 14 is suppressed from being worn. The reliability of the scroll compressor 2 can be improved.

However, as shown in FIG. 13, since the swirl scroll plate-shaped spiral tooth 12b of the swivel scroll 12 receives a load in the radial direction A2, the swivel scroll 12 is in a motion state of swinging due to revolution with a slight inclination. May become. In this case, a gap d is generated between the front end surface of the outer peripheral portion of the fixed scroll 11 on the swivel scroll 12 side and the upper surface of the base plate 12a of the swivel scroll 12. When this gap d is generated, the intermediate pressure refrigerant RM in the intermediate pressure chamber 16 leaks to the outer compression portion 40 that compresses the low pressure refrigerant RL. Leakage of the intermediate pressure refrigerant RM to the outer compression section 40 reduces the compression efficiency of the outer compression section 40.

As shown in FIG. 14, the decrease in the compression efficiency of the outer compression unit 40 is due to the increase in the intermediate pressure refrigerant RM in the outer compression unit 40, which increases the pressure in the outer compression unit 40 and increases the compression power for the region E10. Is. Further, as shown in FIG. 15, when the intermediate pressure refrigerant having a temperature higher than that of the low pressure refrigerant of the outer compression portion 40 leaks to the outer compression portion 40, the low pressure refrigerant is heated as shown by the arrow A10 and compressed by the outer compression portion 40. As shown by arrow A11, the intermediate pressure refrigerant is heated to a higher temperature than the ideal intermediate pressure refrigerant. When the high temperature intermediate pressure refrigerant is introduced into the inner compression unit 41, the density of the intermediate pressure refrigerant in the inner compression unit 41 decreases, so that the volumetric efficiency of the inner compression unit 41 decreases.

Therefore, in the third embodiment, as shown in FIG. 13, the fixed scroll 11 is formed with an outer wall 11c having a U-shaped axial cross section of the swivel scroll 12, and the tip surface of the outer wall 11c and the swivel scroll. A ring-shaped seal is provided on the sliding surface of the 12 base plate 12a. In FIGS. 16 and 17, a ring-shaped seal 70 is provided on the front end surface side of the outer wall 11c.

As shown in FIG. 18, the ring-shaped seal 70 may be provided on the base plate 12a side of the swivel scroll 12. Further, the shape of the ring-shaped seal 70 is not limited to a circular shape, and may be an elliptical shape or a polygonal shape according to the usage pattern.

(Thermal expansion absorption part of the ring-shaped seal)
By the way, the ring-shaped seal 70 is formed of, for example, resin or metal. However, the ring-shaped seal 70 is thermally expanded due to the temperature rise accompanying the operation of the scroll compressor 2. In particular, the ring-shaped seal 70 has a long peripheral length as compared with the width and thickness, and during thermal expansion, the elongation in the circumferential direction is installed in the groove and restrained, so that thermal stress is generated and further in the axial direction. It may be damaged due to biting due to deformation of.

Therefore, it is preferable that the ring-shaped seal 70 is provided with a thermal expansion absorption portion that absorbs thermal expansion during thermal expansion. For example, as shown in FIG. 19, a split gap 71 is provided in a part of the ring-shaped seal 70 as a relief allowance at the time of thermal expansion. The division gap 71 of FIG. 19 is inclined with respect to the axial direction of the swivel scroll 12. Here, the circumferential width d10 of the split gap 71 is a value corresponding to the amount of thermal expansion during thermal expansion. Further, since the split gap 71 is constrained by the groove, it is preferable to provide a plurality of split gaps 71 in the circumferential direction. By providing the dividing gap 71, it is possible to avoid biting during thermal expansion, and it is possible to reliably block refrigerant leakage.

Further, as shown in FIG. 20, the division gap 72 may be provided instead of the division gap 71. The split gap 72 is inclined with respect to the circumferential direction of the swivel scroll 12 or the fixed scroll 11. Here, the circumferential width d20 of the split gap 72 is a value corresponding to the amount of thermal expansion during thermal expansion. Further, since the split gaps 72 are constrained by the grooves, it is preferable to provide a plurality of split gaps 72 in the circumferential direction. By providing the dividing gap 72, it is possible to avoid biting during thermal expansion, and it is possible to reliably block refrigerant leakage.

Further, as shown in FIG. 21, the ring-shaped seal 70 is sandwiched between the outer peripheral surface 70a and the inner peripheral surface 70b instead of the divided gaps 71 and 72, and is formed in a region not including the outer peripheral surface 70a and the inner peripheral surface 70b. One or more space portions 73 may be provided. The space portion 73 absorbs thermal expansion by crushing the space portion 73 during thermal expansion, suppresses deformation of the outer shape of the ring-shaped seal 70, and more reliably leaks refrigerant as compared with a ring-shaped seal having a split gap. It can be blocked.

The third embodiment can be applied to a general scroll compressor other than the two-stage compression scroll compressor shown in the first embodiment described above. For example, it can be applied to a scroll compressor with one-stage compression.

(Example of applicable heat cycle)
In the above-described first to third embodiments, the thermodynamic cycle system shown in FIGS. 1 and 2 is shown as an example of the thermodynamic cycle system that employs the two-stage compression two-stage expansion cycle. However, the scroll compressor 2 shown in the first to third embodiments can be applied to a thermodynamic cycle system other than the thermodynamic cycle system shown in FIGS. 1 and 2.

For example, as shown in FIGS. 22 and 23, the supercooler 4 may be deleted from the thermodynamic cycle system 1 shown in FIG.

Further, as shown in FIGS. 24 and 25, in the thermal cycle system of FIGS. 22 and 23, between the intermediate pressure refrigerant RM2 separated by the gas-liquid separator 6 and the low pressure refrigerant RL led out from the evaporator 8. An internal heat exchanger 9 for heat exchange may be provided.

Further, as shown in FIGS. 26 and 27, in the thermal cycle system of FIGS. 1 and 2, the high-pressure refrigerant RH immediately before being introduced into the high-stage expansion valve 5 and the low-pressure refrigerant RL derived from the evaporator 8 are used. An internal heat exchanger 9a for exchanging heat between the two may be provided.

Further, as shown in FIGS. 28 and 29, the gas-liquid separator 6 of the heat cycle system 1 shown in FIG. 1 is deleted, and the high-pressure refrigerant RH derived from the supercooler 4 is branched at the branch point PS. An internal heat exchanger in which one of the branched high-pressure refrigerants RH is introduced into the intermediate expansion valve 5a and expanded under reduced pressure, and heat is exchanged between the intermediate-pressure refrigerant expanded under reduced pressure and the other high-pressure refrigerant not expanded under reduced pressure. 9b is provided. The internal heat exchanger 9b heats the adiabatically expanded intermediate pressure refrigerant by using the heat of the other high pressure refrigerant that is not expanded under reduced pressure. This intermediate pressure refrigerant is directly introduced into the high-stage compression chamber of the scroll compressor 2. On the other hand, the high-pressure refrigerant that is not adiabatically expanded via the internal heat exchanger 9b is introduced into the low-stage expansion valve 7 and expanded under reduced pressure to become an intermediate pressure refrigerant.

[Embodiment 4]
Next, the fourth embodiment will be described. FIG. 30 is a vertical cross-sectional view showing the configuration of the scroll compressor 102 according to the fourth embodiment. Further, FIG. 31 is a perspective view of the scroll compressor 102 shown in FIG. 30 as viewed diagonally from the right. Further, FIG. 32 is a perspective view of the scroll compressor 102 shown in FIG. 30 as viewed obliquely from the left. Further, FIG. 33 is a perspective view of the refrigerant connection cover 100 shown in FIG. 30 as viewed from the back surface side (Y direction). Further, FIG. 34 is a front view of the state in which the refrigerant connection cover 100 is attached. Further, FIG. 35 is a front view of the state in which the refrigerant connection cover 100 is removed.

In the above-described first to third embodiments, the outer back surface of the fixed scroll 11 is covered with the housing 10a forming the intermediate pressure chamber 16 and the high pressure chamber 17, and is connected to the housing 10b. On the other hand, as shown in FIGS. 30 to 35, in the fourth embodiment, the intermediate pressure refrigerants RM1 and RM3 are sucked and the intermediate pressure refrigerant RM1 is sucked on the back surface of the fixed scroll 11 facing the outside (Y direction). , The refrigerant connection cover 100 that forms the intermediate pressure refrigerant chamber 116 that discharges the intermediate pressure refrigerant RM4 that merges RM3 and the high pressure refrigerant chamber 117 that sucks and discharges the high pressure refrigerant RH is directly attached. The intermediate pressure refrigerant chamber 116 and the high pressure refrigerant chamber 117 formed between the refrigerant connection cover 100 and the fixed scroll 11 are each sealed by an O-ring or the like. The thrust bearing mechanism 114 has a thrust bearing mechanism and a rotation suppressing mechanism of the swivel scroll 12, and three thrust bearing mechanisms 114 are provided on the XZ plane. The refrigerant connection cover 100 is detachably attached to the housing 10.

By attaching the refrigerant connection cover 100 directly to the fixed scroll 11, the refrigerant connection cover 100 can be removed independently of the housing 10 without being affected by the housing 10 (housing 10c) composed of the housings 10c and 10d. It is possible to improve maintainability and compactness. As shown in FIG. 30, the housing 10c is fixed to the fixed scroll 11, and the fixed scroll 11 constitutes a part of the housing 10. Moreover, since the refrigerant connection cover 100 does not need to have the function of a housing, a large number of valves, openings, and pipes peculiar to two-stage compression can be integrated.

The intermediate pressure refrigerant chamber 116 is formed so that the recess 105 on the fixed scroll 11 side and the recess 106 on the refrigerant connection cover 100 side face each other. Similarly, the high-pressure refrigerant chamber 117 is formed so that the recess 107 on the fixed scroll 11 side and the recess 108 on the refrigerant connection cover 100 side face each other. The intermediate pressure refrigerant chamber 116 and the high pressure refrigerant chamber 117 are separated by a partition wall 101.

In the recess 105, the intermediate pressure refrigerant discharge port 123 corresponding to the intermediate pressure refrigerant discharge port 23 communicating with the outer compression portion 40 and the intermediate pressure refrigerant suction port 122 corresponding to the intermediate pressure refrigerant suction port 22 communicating with the inner compression portion 41 , And the outlet opening 151 of the intermediate pressure relief hole 141 communicating with the outer compression portion 40 is formed. On the other hand, the recess 106 is formed with an external intermediate pressure refrigerant connection suction port 126 for sucking the gas intermediate pressure refrigerant RM1 sucked from the external gas-liquid separator 6.

As shown in FIGS. 30 to 32, the intermediate pressure refrigerant RM1 is introduced into the housing 10d from the external intermediate pressure refrigerant suction port 130 together with the oil, and the housing intermediate pressure refrigerant is sucked through the seal inside the housing 10. Reach mouth 131. The intermediate pressure refrigerant suction port 131 of the housing and the external intermediate pressure refrigerant connection suction port 126 are connected by an intermediate pipe LM. Therefore, the intermediate pressure refrigerant RM1 sucked from the housing intermediate pressure refrigerant suction port 131 is introduced into the intermediate pressure refrigerant chamber 116 via the external intermediate pressure refrigerant connection suction port 126. The intermediate pipe LM is a pipe (see FIG. 1) that introduces the gas-phase intermediate pressure refrigerant RM1 separated by the gas-liquid separator 6 into the intermediate pressure refrigerant chamber 116, and partially interposes the housing 10. It is a pipe.

The intermediate pressure refrigerant RM1 introduced into the intermediate pressure refrigerant chamber 116 and the intermediate pressure refrigerant RM3 discharged from the intermediate pressure refrigerant discharge port 123 merge in the intermediate pressure refrigerant chamber 116 and suck in the intermediate pressure refrigerant as the intermediate pressure refrigerant RM4. It is discharged from the port 122 to the inner compression unit 41.

The fixed scroll 11 is provided with a low-pressure refrigerant suction port 121 corresponding to the low-pressure refrigerant suction port 21, and the low-pressure refrigerant RL is sucked into the outer compression unit 40 via the low-pressure refrigerant suction port 121.

On the other hand, the recess 107 is formed with a high-pressure refrigerant discharge port 124 corresponding to the high-pressure refrigerant discharge port 24 and an outlet opening 152 of the high-pressure relief hole 151 communicating with the outer compression portion 40. Further, the recess 108 is formed with a high-pressure refrigerant external discharge port 125 for discharging the high-pressure refrigerant RH of the high-pressure refrigerant chamber 117 to the outside.

A check valve V1 is provided in the recess 105 of the intermediate pressure refrigerant chamber 116 to prevent the intermediate pressure refrigerant RM3 from flowing back from the intermediate pressure refrigerant discharge port 123 to the outer compression portion 40. Further, a check valve V2 for preventing the high-pressure refrigerant RH from flowing back from the high-pressure refrigerant discharge port 124 to the inner compression portion 41 is provided in the recess 107 of the high-pressure refrigerant chamber 117.

Further, in the recess 105 of the intermediate pressure refrigerant chamber 116, in order to suppress the refrigerant pressure of the outer compression portion 40 to the first predetermined pressure or less, an intermediate pressure is provided in the outlet opening 151 of the intermediate pressure relief hole 141 (see FIGS. 6 and 35). An intermediate pressure relief valve V11, which is a relief means, is provided. Further, in the recess 107 of the high-pressure refrigerant chamber 117, in order to suppress the refrigerant pressure of the inner compression portion 41 to a second predetermined pressure or less, a high-pressure relief means is used at the outlet opening 152 of the high-pressure relief hole 142 (see FIGS. 6 and 35). A high pressure relief valve V12 is provided.

The intermediate pressure refrigerant discharge port 123, the intermediate pressure refrigerant suction port 122, and the high pressure refrigerant discharge port 124 are formed on the housing 10 side, and the refrigerant connection cover 110 having an external intermediate pressure refrigerant connection introduction port 126 and a high pressure refrigerant outlet port 125 is provided. By being attached to the housing 10, the intermediate pressure refrigerant chamber 116 and the high pressure refrigerant chamber 117 are formed.

Further, the intermediate pressure refrigerant suction port 122, the intermediate pressure refrigerant discharge port 123, and the external intermediate pressure refrigerant connection introduction port 126 communicate with the intermediate pressure refrigerant chamber 116, and the high pressure refrigerant discharge port 124 and the high pressure refrigerant outlet port 125 are high pressure refrigerants. It communicates with room 127. The intermediate pressure refrigerant suction port 122 and the high pressure refrigerant discharge port 124 are opened in the same direction as the intermediate pressure refrigerant discharge port 123. The housing intermediate pressure refrigerant suction port 131 opens in the same direction as the housing intermediate pressure refrigerant discharge port 123, and discharges the intermediate pressure refrigerant through the seal inside the housing 10.

The intermediate pressure relief valve V11, the high pressure relief valve V12, the check valve V1, and the check valve V2 appear on the surface of the housing 10 when the refrigerant connection cover 100 is removed, so that maintainability is improved. Can be done.

Here, the volume of the intermediate pressure refrigerant chamber 116 is larger than the volume of the high pressure refrigerant chamber 117. That is, since the intermediate pressure refrigerants RM1, RM3, and RM4 have a lower density than the high pressure refrigerant RH and pressure loss is likely to occur, the pressure loss is reduced by increasing the volume of the intermediate pressure refrigerant chamber 116.

In FIGS. 30 to 35, the depth d1 of the intermediate pressure refrigerant chamber 116 and the depth d2 of the high pressure refrigerant chamber 117 are made the same, and the cross-sectional area of the intermediate pressure refrigerant chamber 116 is set to the cross-sectional area of the high pressure refrigerant chamber 117. By making the ratio larger, the volume of the intermediate pressure refrigerant chamber 116 is increased. Not limited to this, the volume of the intermediate pressure refrigerant chamber 116 may be increased by making the depth d1 of the intermediate pressure refrigerant chamber 116 deeper than the depth d2 of the high pressure refrigerant chamber 117. In this case, since the pressure of the intermediate pressure refrigerant is smaller than the pressure of the high pressure refrigerant, the wall thickness of the refrigerant connection cover 100 around the intermediate pressure refrigerant chamber 116 can be reduced, so that the depth d2 is increased. That is easy.

Further, when changing the volume of the intermediate pressure refrigerant chamber 116 or the high pressure refrigerant chamber 117, the structure on the housing 10 side is controlled by controlling the volume (depth) of the recess 106 or the recess 108 formed on the refrigerant connection cover 100 side. The volumes of the intermediate pressure refrigerant chamber 116 and the high pressure refrigerant chamber 117 can be changed without changing.

The notch 140 provided in the refrigerant connection cover 100 is used for positioning when the refrigerant connection cover 100 is attached.

When heating using the above-mentioned condenser 3, the heat cycle system becomes a heat pump system, and when cooling using the evaporator 8, the heat cycle system becomes a normal refrigeration system.

Further, the scroll compressor 2 described above is a two-stage compressor having an outer compression unit 40 and an inner compression unit 41, but the present invention is not limited to this, and a multi-stage compressor may be used.

1 Thermodynamic cycle system 2,102 Scroll compressor 3 Condenser 4 Supercooler 5 High-stage expansion valve 5a Intermediate expansion valve 6 Gas-liquid separator 7 Low-stage expansion valve 8 Evaporator 9, 9a, 9b Internal heat exchanger 10, 10a, 10b, 10c, 10d Housing 11 Fixed scroll 11a, 12a Base plate 11b Fixed scroll plate-shaped spiral tooth 11c Outer wall 12 Swing scroll 12b Swirling scroll plate-shaped spiral tooth 13 Crank shaft 14 Thrust bearing 15 Balance weight 16 Intermediate pressure chamber 17 High pressure chamber 18 Discharge valve 20 Divided wall 21,121 Low pressure refrigerant suction port 22,122 Intermediate pressure refrigerant suction port (intermediate pressure refrigerant outlet)
23,123 Intermediate pressure refrigerant discharge port (intermediate pressure refrigerant introduction port)
24,124 High-pressure refrigerant discharge port (high-pressure refrigerant introduction port)
30, 31 Fixed scroll plate-shaped spiral tooth 32, 33 Swirling scroll plate-shaped spiral tooth 40 Outer compression part 41 Inner compression part 51, 52 Chip seal 60-1 First inner compression chamber 60-2 Second inner compression chamber 61-0 Outer compression chamber 61-1 1st outer compression chamber 61-2 2nd outer compression chamber 70 Ring-shaped seal 70a Outer peripheral surface 70b Inner peripheral surface 71,72 Divided gap 73 Space 100 Coolant connection cover 101 Partition wall 105-108 Recessed 116 Intermediate Pressure refrigerant room 117 High pressure refrigerant room 114 Thrust bearing mechanism 125 High pressure refrigerant outlet 126 External intermediate pressure refrigerant connection introduction port 130 External intermediate pressure refrigerant suction port 131 Housing intermediate pressure refrigerant suction port 141 Intermediate pressure relief hole 142 High pressure relief hole 151 152 Outlet opening AL Rotation direction d Gap E Divided area GH, GL, GM Refrigerant circulation amount L1 Low pressure refrigerant suction pipe L2 Intermediate pressure refrigerant suction pipe L3 High pressure refrigerant discharge pipe LM Intermediate pipe V1, V2 Check valve V11 Check valve (V11) Intermediate pressure relief means)
V12 high pressure relief valve (high pressure relief means)
θA communication angle

Claims (7)

Multiple compression chambers provided in the housing and
An intermediate pressure refrigerant discharge port that discharges an intermediate pressure refrigerant from the lower compression chambers of the plurality of compression chambers,
An intermediate pressure refrigerant suction port that opens in the same direction as the intermediate pressure refrigerant discharge port and sucks the intermediate pressure refrigerant into the higher stage side of the plurality of compression chambers.
A high-pressure refrigerant discharge port that opens in the same direction as the intermediate pressure refrigerant discharge port and discharges the high-pressure refrigerant discharged from the high-stage side compression chambers of the plurality of compression chambers.
An intermediate-pressure refrigerant chamber that is detachably attached to the housing and has an external intermediate-pressure refrigerant connection introduction port that communicates with the intermediate-pressure refrigerant suction port and the intermediate-pressure refrigerant discharge port and opens to the outside, and the high-pressure refrigerant. A refrigerant connection cover that forms a high-pressure refrigerant chamber that communicates with the discharge port and has a high-pressure refrigerant outlet that opens to the outside.
Equipped with a,
The intermediate pressure refrigerant chamber is formed so that the first recess on the housing side and the second recess on the refrigerant connection cover side, which have a flat bottom, face each other, and the depth of the first recess is greater than the depth of the second recess. Shallow,
The high-pressure refrigerant chamber is formed by the third recess on the housing side having a flat bottom and the fourth recess on the refrigerant connection cover side facing each other, and the depth of the third recess is shallower than the depth of the fourth recess. ,
A multi-stage compressor characterized in that the volume of the intermediate pressure refrigerant chamber is larger than the volume of the high pressure refrigerant chamber. When the internal pressure of the high-stage compression chamber becomes a predetermined value or more, a high-pressure relief means for communicating the high-stage compression chamber and the high-pressure refrigerant chamber is provided in the third recess .
When the internal pressure of the low-stage compression chamber becomes a predetermined value or more, an intermediate pressure relief means for communicating the low-stage compression chamber and the intermediate-pressure refrigerant chamber is provided in the first recess. The multi-stage compressor according to claim 1. A check valve for preventing backflow from the intermediate pressure refrigerant discharge port to the compression chamber is provided in the first recess .
The multi-stage compressor according to claim 1, wherein a check valve for preventing backflow from the high-pressure refrigerant discharge port to the compression chamber is provided in the third recess. The housing is formed with a housing intermediate pressure refrigerant suction port that opens in the same direction as the intermediate pressure refrigerant discharge port and discharges the intermediate pressure refrigerant through a seal inside the housing.
The multi-stage compressor according to claim 1, wherein the housing intermediate pressure refrigerant suction port and the external intermediate pressure refrigerant connection introduction port are connected by a pipe. The multi-stage compressor is a scroll compressor provided with a swivel scroll and a fixed scroll.
The multi-stage compressor according to claim 1, wherein the fixed scroll constitutes a part of the housing, and the refrigerant connection cover is attached to the fixed scroll. The multi-stage compressor according to claim 1, wherein the refrigerant connection cover is provided with a notch for positioning. A multi-stage compressor according to any one of claims 1 to 6 , wherein the multi-stage compressor is used in a two-stage compression two-stage expansion thermodynamic cycle system.

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