JP6926637B2 - Scroll compressor - Google Patents

Description

The present invention relates to a scroll compressor capable of preventing the occurrence of overcompression at the time of discharging the intermediate pressure refrigerant in the outer compression portion and suppressing a decrease in the efficiency of the compressor.

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, a scroll compressor that compresses the refrigerant in the compression chamber by engaging the fixed scroll plate-shaped spiral teeth and the swivel scroll plate-shaped spiral teeth with each other to form a compression chamber and causing the swirling scroll plate-shaped spiral teeth to revolve. A split wall for dividing the compression chamber into an outer compression portion and an inner compression portion is provided between the winding start on the center side and the outer winding end of the fixed scroll plate-shaped spiral tooth, and the swivel scroll plate shape is provided. In a scroll compressor in which the spiral teeth are divided so as not to interfere with the dividing wall due to the revolving motion, the scroll compressor is provided in the outer compression portion on the low pressure side divided by the dividing wall and is sucked from the low pressure refrigerant suction port. An intermediate pressure refrigerant discharge port is provided to compress and discharge the compressed refrigerant to an intermediate pressure.

In the outer compression portion, an inner compression chamber is formed inside the swirl scroll plate-shaped spiral tooth, and an outer compression chamber is formed outside the swirl scroll plate-shaped spiral tooth. The above-mentioned intermediate pressure refrigerant discharge port discharges the compressed refrigerant from the inner compression chamber and the compressed refrigerant from the outer compression chamber, but when the compressed refrigerant is discharged from the inner compression chamber to the intermediate pressure refrigerant discharge port, it is intermediate. The opening area of the pressure refrigerant discharge port cannot be sufficiently secured, overcompression may occur due to pressure loss at the intermediate pressure refrigerant discharge port, and the efficiency of the scroll compressor may decrease.

The present invention has been made in view of the above, and provides a scroll compressor capable of preventing the occurrence of overcompression at the time of discharging the intermediate pressure refrigerant in the outer compression portion and suppressing a decrease in the efficiency of the compressor. The purpose is.

In order to solve the above-mentioned problems and achieve the object, the scroll compressor according to the present invention forms a compression chamber by engaging the fixed scroll plate-shaped spiral teeth and the swivel scroll plate-shaped spiral teeth with each other to form the swivel scroll. It is a scroll compressor that compresses the refrigerant in the compression chamber by revolving the plate-shaped spiral teeth, and creates the compression chamber between the winding start on the center side and the winding end on the outer side of the fixed scroll plate-shaped spiral teeth. In a scroll compressor provided with a dividing wall that divides into an outer compression part that compresses from low pressure to intermediate pressure and an inner compression part that compresses from intermediate pressure to high pressure, the refrigerant compressed to intermediate pressure by the outer compression part is said to be inside. An intermediate pressure refrigerant discharge port for discharging to the compression portion is provided, and the opening area of the intermediate pressure refrigerant discharge port increases when the discharge pressure of the outer compression portion becomes a first predetermined value higher than the intermediate pressure. It is characterized by that.

Further, in the scroll compressor according to the present invention, in the above invention, the intermediate pressure refrigerant discharge port is provided on the fixed scroll side sliding surface of the fixed scroll and the swirling scroll plate-shaped spiral tooth, and the outer compression portion. A first intermediate pressure refrigerant discharge port that discharges the refrigerant compressed to the intermediate pressure to the inner compression portion, and a refrigerant provided so as to penetrate the dividing wall and compressed to the intermediate pressure by the outer compression portion. A second intermediate pressure refrigerant discharge port for discharging to the inner compression portion is provided, and the second intermediate pressure refrigerant discharge port is opened when the discharge pressure of the outer compression portion becomes equal to or higher than the first predetermined value. It is characterized by.

Further, in the scroll compressor according to the present invention, the fixed scroll plate-shaped spiral tooth and the swivel scroll plate-shaped spiral tooth are meshed with each other to form a compression chamber, and the swirl scroll plate-shaped spiral tooth is revolved to perform the compression. A scroll compressor that compresses the refrigerant in the chamber, and is intermediate between the outer compression portion that compresses the compression chamber from low pressure to intermediate pressure between the winding start on the center side and the outer winding end of the fixed scroll plate-shaped spiral tooth. In a scroll compressor provided with a dividing wall that divides into an inner compression portion that compresses from pressure to high pressure, the scroll compressor is provided with an intermediate pressure refrigerant discharge port that discharges the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion. The intermediate pressure refrigerant discharge port is characterized in that the opening area increases when the pressure difference obtained by subtracting the suction pressure of the inner compression portion from the discharge pressure of the outer compression portion becomes a second predetermined value or more. ..

Further, in the scroll compressor according to the present invention, in the above invention, the intermediate pressure refrigerant discharge port is provided on the fixed scroll side sliding surface of the fixed scroll and the swirling scroll plate-shaped spiral tooth, and the outer compression portion. A first intermediate pressure refrigerant discharge port that discharges the refrigerant compressed to the intermediate pressure to the inner compression portion, and a refrigerant provided so as to penetrate the dividing wall and compressed to the intermediate pressure by the outer compression portion. A second intermediate pressure refrigerant discharge port for discharging to the inner compression portion is provided, and the second intermediate pressure refrigerant discharge port has a pressure difference obtained by subtracting the suction pressure of the inner compression portion from the discharge pressure of the outer compression portion. It is characterized in that it opens when it exceeds the second predetermined value.

Further, in the scroll compressor according to the present invention, in the above invention, the discharge pressure of the outer compression portion where the second intermediate pressure refrigerant discharge port opens is the outer compression where the first intermediate pressure refrigerant discharge port opens. It is characterized in that it is higher than the discharge pressure of the part.

Further, in the scroll compressor according to the present invention, in the above invention, the second intermediate pressure refrigerant discharge port communicates the compression chamber formed inside the swirling scroll plate-shaped spiral tooth with the inner compression portion. It is characterized in that it is provided so as to do so.

According to the present invention, the intermediate pressure refrigerant discharge port increases the opening area when the discharge pressure of the outer compression portion becomes equal to or higher than the first predetermined value higher than the intermediate pressure. Therefore, the intermediate pressure refrigerant is discharged. A sufficient opening area of the port can be secured, overcompression due to pressure loss at the intermediate pressure refrigerant discharge port can be prevented, and a decrease in efficiency of the scroll compressor can be prevented.

FIG. 1 is a circuit diagram showing an outline configuration of a thermodynamic cycle system to which the scroll compressor according to the 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 a diagram showing the opening shape and arrangement position of the conventional intermediate pressure refrigerant discharge port. FIG. 9 is an enlarged view of the vicinity of the intermediate pressure refrigerant discharge port showing the configuration showing the arrangement position of the intermediate pressure refrigerant discharge port. FIG. 10 is a schematic diagram showing a compression circuit of a scroll compressor. FIG. 11 is a PV diagram of the compression chamber when only the first intermediate pressure refrigerant discharge port is provided and when the first intermediate pressure refrigerant discharge port and the second intermediate pressure refrigerant discharge port are provided.

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

(Overview of applicable system)
FIG. 1 is a circuit diagram showing an outline configuration of a thermodynamic cycle system 1 to which the scroll compressor 2 according to the 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. 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-stage side compression chamber and a later-described inner compression unit 41 that functions as a high-stage 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 outer and inner sides 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 in the swirl scroll plate-shaped spiral tooth 32 and the inner compression portion 41. 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 for discharging the intermediate pressure refrigerant RM3 compressed in the outer compression unit 40 to the inner compression unit 41 side is formed. NS. The intermediate pressure refrigerant discharge port includes a first intermediate pressure refrigerant discharge port 23 and a second intermediate pressure refrigerant discharge port 25. The first intermediate pressure refrigerant discharge port 23 is a port that discharges to the intermediate pressure chamber 16. The opening of the intermediate pressure refrigerant discharge port 23 is a division of the fixed scroll side sliding surface S23 (see FIG. 6) on which the tip 32a side (see FIG. 7) of the swirl scroll plate-shaped spiral tooth 32 slides in the outer compression portion 40. It is provided on the wall 20 side. A first check valve 26 (see FIG. 10), which will be described later, is provided between the first intermediate pressure refrigerant discharge port 23 and the intermediate pressure chamber 16. On the other hand, the second intermediate pressure refrigerant discharge port 25 is formed inside (center side) of the dividing wall 20, and discharges the intermediate pressure refrigerant in the outer compression portion 40 directly to the inner compression portion 41 side. A second check valve 27 (see FIGS. 9 and 10), which will be described later, is provided in the second intermediate pressure refrigerant discharge port 25.

An intermediate pressure refrigerant suction port 22 for sucking the intermediate pressure refrigerants RM1 and RM3 through the intermediate pressure chamber 16 is formed at the outer winding end position of the swirl scroll plate-shaped spiral tooth 33 in the inner compression portion 41, and a dividing wall is formed. The second intermediate pressure refrigerant discharge port 25 formed in 20 is connected. Further, a high-pressure refrigerant 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 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.

The outer compression section 40 compresses the compression chamber from low pressure to intermediate pressure, and the inner compression section 41 compresses from intermediate pressure to high pressure. The first check valve 26 and the second check valve 27 are opened when the discharge pressure of the outer compression portion 40 is higher than the intermediate pressure. Further, the second check valve 27 opens when the discharge pressure of the outer compression portion 40 at which the first check valve 26 opens is higher than the discharge pressure. Therefore, the intermediate pressure refrigerant discharge port including the first intermediate pressure refrigerant discharge port 23 and the second intermediate pressure refrigerant discharge port 25 first discharges the first intermediate pressure refrigerant when the discharge pressure of the outer compression portion 40 becomes higher than the intermediate pressure. When the port 23 opens and then the discharge pressure becomes higher, the second intermediate pressure refrigerant discharge port 25 opens. That is, the opening area of the intermediate pressure refrigerant discharge port can be increased when the discharge pressure of the outer compression portion 40 becomes higher than the intermediate pressure.

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.

(Opening of intermediate pressure refrigerant discharge port)
By the way, as shown in FIG. 8, if the second intermediate pressure refrigerant discharge port 25 is not provided and only the first intermediate pressure refrigerant discharge port 23 is provided as the intermediate pressure refrigerant discharge port, the compression in the inner compression chamber 60-2 is performed. When discharging the refrigerant, the opening area of the first intermediate pressure refrigerant discharge port 23 cannot be sufficiently secured, overcompression occurs due to the pressure loss at the first intermediate pressure refrigerant discharge port 23, and the scroll compressor The efficiency of 2 is reduced.

Therefore, in the present embodiment, as described above, the second intermediate pressure refrigerant discharge port 25 provided with the second check valve 27 is provided inside the dividing wall 20. FIG. 9 is an enlarged view of the vicinity of the intermediate pressure refrigerant discharge port showing the configuration showing the arrangement position of the intermediate pressure refrigerant discharge port. Further, FIG. 10 is a schematic diagram showing a compression circuit of the scroll compressor 2.

As shown in FIGS. 9 and 10, a first check valve 26 is provided on the intermediate pressure chamber 16 side of the first intermediate pressure refrigerant discharge port 23. The intermediate pressure refrigerant discharged to the intermediate pressure chamber 16 via the first check valve 26 is discharged to the inner compression unit 41 via the intermediate pressure refrigerant suction port 22. On the other hand, the second intermediate pressure refrigerant discharge port 25 includes an inner compression chamber 60-2 and an inner compression portion 41 formed inside (center side) of the dividing wall 20 and inside the swirl scroll plate-shaped spiral tooth 32. Is provided so as to communicate with each other so that the compressed refrigerant of the outer compression portion 40 can be discharged to the inner compression portion 41 via the second check valve 27.

The first check valve 26 opens when the discharge pressure Pa of the inner compression chamber 60-2 of the outer compression portion 40 is higher than the intermediate pressure Pb. Further, the second check valve 27 opens when the discharge pressure Pa becomes the first predetermined value Pa1 or more, which is higher than the intermediate pressure Pb. The first predetermined value Pa1 is higher than the intermediate pressure Pb. That is, the discharge pressure Pa opened by the second intermediate pressure refrigerant discharge port 25 is higher than the discharge pressure Pa opened by the first intermediate pressure refrigerant discharge port 23. As a result, the combined opening area of the first intermediate pressure refrigerant discharge port 23 and the second intermediate pressure refrigerant discharge port 25 is the first intermediate pressure when the discharge pressure Pa is higher than the intermediate pressure Pb and less than the first predetermined value Pa1. When the opening area of the refrigerant discharge port 23 is limited and the discharge pressure Pa is equal to or higher than the first predetermined value Pa1, the opening area of the second intermediate pressure refrigerant discharge port 25 is added to the opening area of the first intermediate pressure refrigerant discharge port 23. The opening area increases.

The second intermediate pressure refrigerant discharge port 25 is opened when the pressure difference obtained by subtracting the suction pressure Pc of the inner compression unit 41 from the discharge pressure Pa becomes the second predetermined value ΔP or more, and the first intermediate pressure refrigerant is discharged. The combined opening area of the port 23 and the second intermediate pressure refrigerant discharge port 25 may be increased. That is, the second check valve 27 has a function of opening when the pressure difference obtained by subtracting the suction pressure Pc from the discharge pressure Pa becomes the second predetermined value ΔP or more.

By the way, the second check valve 27 has a check valve function and a pressure adjusting function. The pressure adjusting function of the second check valve 27, which opens when the second predetermined value ΔP or more, can be realized by using, for example, a spring. When the pressure difference is less than the second predetermined value ΔP, the second check valve 27 presses the valve body by the repulsive force of the spring provided on the inner compression portion 41 side to close the opening of the valve seat, and the pressure difference becomes large. When it becomes the second predetermined value ΔP or more, the repulsive force of the spring is overcome and the valve body is pushed toward the inner compression portion 41 to open the opening of the valve seat. Therefore, the second predetermined value ΔP can be set by adjusting the repulsive force of the spring. The spring is not limited to the compression spring, and a torsion spring may be used to open and close the opening of the valve seat with a plate-shaped valve body.

Further, when the capacity of the intermediate pressure chamber 16 is large, the intermediate pressure Pb becomes substantially constant. In this case, the above-mentioned first predetermined value Pa is a value obtained by adding the intermediate pressure Pb and the pressure applied to the valve body by the repulsive force of the spring. Therefore, the first predetermined value Pa can be set by adjusting the repulsive force of the spring.

Here, the discharge pressure Pa at which the second intermediate pressure refrigerant discharge port 25 opens is a value at which the inner compression chamber 60-2 approaches the overcompressed state when only the first intermediate pressure refrigerant discharge port 23 is open. Is preferable.

As a result, when the discharge pressure Pa becomes the first predetermined value Pa1 or more, or when the pressure difference obtained by subtracting the suction pressure Pc from the discharge pressure Pa becomes the second predetermined value ΔP or more, the second intermediate pressure refrigerant is discharged. The port 25 opens to increase the combined opening area of the intermediate pressure refrigerant discharge port, and a part of the compressed intermediate pressure refrigerant is discharged to the inner compression portion 41 via the second intermediate pressure refrigerant discharge port 25. As a result, it is possible to prevent the discharge pressure Pa of the inner compression chamber 60-2 from being in an overcompressed state, and to prevent a decrease in the efficiency of the scroll compressor 2.

FIG. 11 (a) is a PV diagram of the compression chamber when only the first intermediate pressure refrigerant discharge port 23 is provided, and FIG. 11 (b) shows the first intermediate pressure refrigerant discharge port 23 and the second intermediate pressure. The PV diagram of the compression chamber when the refrigerant discharge port 25 is provided is shown. As shown in FIG. 11A, when only the first intermediate pressure refrigerant discharge port 23 is provided, the loss region S21 appears due to overcompression of the compression chamber. On the other hand, as shown in FIG. 11B, when the second intermediate pressure refrigerant discharge port 25 is provided, the overcompression of the compression chamber is reduced, the loss region S21 becomes a small loss region S22, and the scroll compressor 2 Efficiency is improved.

The second check valve 27 may be provided in the second intermediate pressure refrigerant discharge port 25, or may be provided on the inner compression portion 41 side of the second intermediate pressure refrigerant discharge port 25. Further, the mechanism and structure of the second check valve 27 are arbitrary as long as they can withstand the discharge pressure.

1 Thermal cycle system 2 Scroll compressor 3 Condenser 4 Supercooler 5 High-stage expansion valve 6 Gas-liquid separator 7 Low-stage expansion valve 8 Evaporator 10, 10a, 10b Housing 11 Fixed scroll 11a, 12a Base plate 11b Fixed Scroll plate-shaped spiral tooth 12 Swivel scroll 12b Swivel 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 Low pressure refrigerant suction port 22 Intermediate pressure refrigerant suction port 23 No. 1 Intermediate pressure refrigerant discharge port 24 High pressure refrigerant port 25 Second intermediate pressure refrigerant discharge port 26 First check valve 27 Second check valve 30, 31 Fixed scroll plate-shaped spiral teeth 32, 33 Swirling scroll plate-shaped spiral teeth 40 Outside Compression unit 41 Inner compression unit 51, 52 Chip seal 60-2 Inner compression chamber AL Rotation direction E Divided area GH Refrigerant circulation amount GL Refrigerant circulation amount GM Refrigerant circulation amount L1 Low pressure refrigerant suction pipe L2 Intermediate pressure refrigerant suction pipe L3 High pressure refrigerant discharge Piping P1 to P7 Point Pa Discharge pressure Pa1 First predetermined value Pb Intermediate pressure Pc Suction pressure PA, PB Position RH High pressure refrigerant RL Low pressure refrigerant RM, RM1 to RM3 Intermediate pressure refrigerant S21, S22 Loss area S23 Fixed scroll side sliding surface ΔP Second predetermined value

Claims (4)

A scroll compressor that compresses the refrigerant in the compression chamber by engaging the fixed scroll plate-shaped spiral teeth and the swivel scroll plate-shaped spiral teeth with each other to form a compression chamber and causing the swirl scroll plate-shaped spiral teeth to revolve. Between the start of winding on the center side and the end of winding on the outer side of the fixed scroll plate-shaped spiral tooth, the outer compression part that compresses the compression chamber from low pressure to intermediate pressure and the inner compression part that compresses from intermediate pressure to high pressure. In a scroll compressor provided with a dividing wall to divide,
An intermediate pressure refrigerant discharge port for discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion is provided.
The intermediate pressure refrigerant discharge port is
A first intermediate pressure refrigerant discharge port provided on the fixed scroll side sliding surface of the fixed scroll and the swirl scroll plate-shaped spiral tooth and discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion. ,
A second intermediate pressure refrigerant discharge port provided so as to penetrate the dividing wall and discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion.
With
The scroll compressor, characterized in that the second intermediate pressure refrigerant discharge port is opened when the discharge pressure of the outer compression portion becomes a first predetermined value higher than the intermediate pressure. A scroll compressor that compresses the refrigerant in the compression chamber by engaging the fixed scroll plate-shaped spiral teeth and the swivel scroll plate-shaped spiral teeth with each other to form a compression chamber and causing the swirl scroll plate-shaped spiral teeth to revolve. Between the start of winding on the center side and the end of winding on the outer side of the fixed scroll plate-shaped spiral tooth, the outer compression part that compresses the compression chamber from low pressure to intermediate pressure and the inner compression part that compresses from intermediate pressure to high pressure. In a scroll compressor provided with a dividing wall to divide,
An intermediate pressure refrigerant discharge port for discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion is provided.
The intermediate pressure refrigerant discharge port is
A first intermediate pressure refrigerant discharge port provided on the fixed scroll side sliding surface of the fixed scroll and the swirl scroll plate-shaped spiral tooth and discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion. ,
A second intermediate pressure refrigerant discharge port provided so as to penetrate the dividing wall and discharging the refrigerant compressed to the intermediate pressure by the outer compression portion to the inner compression portion.
With
The scroll characterized in that the second intermediate pressure refrigerant discharge port is opened when the pressure difference obtained by subtracting the suction pressure of the inner compression portion from the discharge pressure of the outer compression portion becomes the second predetermined value or more. Compressor. Discharge pressure of the outer compression unit, wherein the second intermediate-pressure refrigerant discharge port is opened, the claim 1 wherein the first intermediate-pressure refrigerant discharge port may be higher than the discharge pressure of the outer compression unit for opening or 2. The scroll compressor according to 2. Claims 1 to 3 characterized in that the second intermediate pressure refrigerant discharge port is provided so as to communicate the compression chamber formed inside the swirl scroll plate-shaped spiral tooth and the inner compression portion. The scroll compressor according to any one of the above.

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