JP2021038682A - Compressor with injection mechanism - Google Patents

Abstract

To provide a compressor with an injection mechanism that can prevent capacity degradation due to heat exchange between injection refrigerant and refrigerant inside a closed vessel.SOLUTION: A compressor with an injection mechanism has second thermal resistance between an intermediate pressure chamber 41 into which refrigerant flows from an injection pipe 95 and an internal space 7 which is larger than first thermal resistance between the internal space 7 of a closed vessel 1 and a discharge chamber 31. Accordingly, thermal resistance of a partition member 45 between the internal space 7 of the closed vessel 1 and the intermediate pressure chamber 41 is increased to suppress heat exchange therebetween; thus, highly efficient operation is allowed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a compressor with an injection mechanism used in an injection cycle.

Patent Document 1 shows a compressor with an injection mechanism used in a conventional injection cycle. As shown in FIG. 11, this compressor includes a closed container 100, a fixed scroll 101 provided in the closed container 100, a swirl scroll 103 that meshes with the fixed scroll 101 to form a compression chamber 102, and discharge from the compression chamber 102. A discharge chamber 104 for smoothing the pulsation of the refrigerant, an intermediate pressure chamber 105 provided adjacent to the discharge chamber 104, an injection pipe (not shown) for introducing the injection refrigerant into the intermediate pressure chamber 105, and the intermediate pressure chamber 105. A check valve 106 provided between the compression chamber 103 and the compression chamber 103 is provided.

Japanese Patent No. 3745801

The present disclosure provides a compressor with an injection mechanism that suppresses heat transfer generated between a discharge refrigerant and an injection refrigerant and has high operating efficiency.

The compressor with an injection mechanism of the present disclosure has a compression mechanism unit that sucks a low-pressure working fluid into a closed container and compresses it into a high-pressure state, and discharges the compressor from the compression chamber in the compression mechanism to the discharge chamber. In a compressor in which the working fluid is sent out of the closed container from the discharge pipe via the internal space around the compression mechanism, the working fluid in an intermediate pressure state between low pressure and high pressure is sent to the outside of the closed container. An intermediate pressure chamber and a discharge chamber, which have an injection pipe for drawing in from the compressor and into which the working fluid guided from the injection pipe flows, are both provided adjacent to the compression chamber to partition the internal space, the intermediate pressure chamber, and the discharge chamber. The partition member has a configuration in which the second thermal resistance, which is the thermal resistance between the internal space and the intermediate pressure chamber, is larger than the first thermal resistance, which is the thermal resistance between the internal space and the discharge chamber.

The thermal resistance referred to here represents the difficulty of heat transfer, and when the temperature difference ΔT of each fluid on both surfaces of the partition member, the partition member area A, and the heat flux q are taken, the thermal resistance K = ΔT / (qxA). ), Which can be rephrased as the temperature difference required to pass a unit of heat. Conversely, when the temperature difference ΔT is fixed, the amount of heat (q xA) transferred between adjacent fluids via the partition member is inversely proportional to the thermal resistance K, and the thermal resistance K. Since the amount of heat exchange between the internal space and the fluid in the intermediate pressure chamber can be suppressed by increasing the size, it is possible to provide a compressor with an injection mechanism that minimizes the decrease in the temperature of the discharged refrigerant and the decrease in the injection rate. It will be possible.

According to the present disclosure, it is possible to suppress a decrease in discharge temperature due to the injection refrigerant and heat reception of the injection refrigerant in the intermediate pressure chamber, and to guide the injection refrigerant to the compression chamber while maintaining a high density. Therefore, it is possible to provide a compressor with a high-performance and high-efficiency injection mechanism.

Longitudinal sectional view of the scroll compressor with an injection mechanism according to the first embodiment. An enlarged cross-sectional view showing a main part of the compressor with an injection mechanism according to the first embodiment. FIG. 2C-C line arrow view Explanatory drawing which shows the positional relationship between the communication passage with a back pressure chamber and a seal member with the turning motion of the compressor with an injection mechanism which concerns on Embodiment 1. The figure which shows the opening state of the communication passage with the back pressure chamber and the injection port by the swinging motion of the compressor with an injection mechanism which concerns on Embodiment 1. The refrigerating cycle diagram of the refrigerating cycle apparatus configured by using the compressor with the injection mechanism according to the first embodiment. AA line arrow view of FIG. BB line arrow view of FIG. An enlarged cross-sectional view showing a main part of the scroll compressor according to the second embodiment. An enlarged cross-sectional view showing a main part of the scroll compressor according to the third embodiment. Longitudinal section of a scroll compressor with a conventional injection mechanism

(Knowledge, etc. that was the basis of this disclosure)
At the time when the inventors came up with the present disclosure, there was a scroll compressor described in Patent Document 1. As shown in FIG. 11, this compressor with an injection mechanism guides the injection refrigerant to the intermediate pressure chamber 105, equalizes the pulsation caused by the injection refrigerant by the intermediate pressure chamber 105, suppresses propagation to the outside of the compressor, and is low. It is noisy.

However, in the above-mentioned conventional configuration, heat transfer occurs between the injection refrigerant and the discharge refrigerant, and the operating efficiency of the compressor is lowered.

That is, since the compressed refrigerant is discharged to the outside via the inside of the closed container in the compressor, the surface of the partition member 107 that separates the inside of the closed container, the discharge chamber 104, and the intermediate pressure chamber 105 is heated to a high temperature state. .. On the other hand, since the injection refrigerant has a medium temperature, the intermediate pressure chamber 105 into which the injection refrigerant is introduced is in a medium temperature state. Therefore, the partition member 107 that separates the intermediate pressure chamber 105 and the space inside the closed container is sandwiched between the high-temperature and medium-temperature refrigerants and has a large temperature gradient. Heat transfer occurs to the injection refrigerant of. As a result, on the discharge refrigerant side, the heating capacity and heating capacity of the air conditioner and hot water supply device decrease due to the temperature decrease, and on the injection refrigerant side, the injection rate decreases due to the decrease in density due to the temperature increase, resulting in efficiency deterioration. There are challenges. The inventors have discovered such a problem and have come to construct the subject matter of the present disclosure in order to solve the problem.

Therefore, the present disclosure provides a compressor with an injection mechanism that suppresses heat transfer generated between the discharge refrigerant and the injection refrigerant and has high operating efficiency.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, duplicate description for substantially the same configuration may be omitted. This is to prevent the following explanation from becoming unnecessarily redundant and to facilitate the understanding of those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 8.

[1-1. Constitution]
FIG. 1 is a vertical cross-sectional view of a scroll compressor shown as an example of a compressor with an injection mechanism according to a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a main part of the scroll compressor of FIG. Hereinafter, the operation and operation of the scroll compressor according to the present embodiment will be described.

As shown in FIG. 1, the scroll compressor 91 according to the present embodiment includes a closed container 1, a compression mechanism 2 located inside the closed container 1, a motor unit 3 for driving the compression mechanism 2, and a closed container. It is provided with an oil storage unit 20 provided at the bottom of 1.

As shown in FIG. 2, the compression mechanism 2 has a main bearing member 11 fixed in the closed container 1 by welding or shrink fitting, and is bolted onto the main bearing member 11 to erect a spiral wrap on the end plate. The fixed scroll 12 to be used, the swivel scroll 13 to erect a spiral wrap on the end plate, the compression chamber 15 formed by engaging the fixed scroll 12 and the swivel scroll 13, and the pressure to press the swivel scroll 13 against the fixed scroll 12. It is provided with a back pressure chamber 29 for holding the back pressure chamber 29.

A rotation restraint mechanism 14 is provided between the rotation scroll 13 and the main bearing member 11 by an old dam ring or the like that prevents the rotation of the rotation scroll 13 and guides it to move in a circular orbit.

The shaft 4 is rotationally driven by the motor unit 3. The shaft 4 is pivotally supported by the main bearing member 11, and the swivel scroll 13 is eccentrically driven by the eccentric shaft portion 4a at the upper end of the shaft 4.

As a result, the swivel scroll 13 is made to move in a circular orbit, and the compression chamber 15 formed between the fixed scroll 12 and the swivel scroll 13 moves from the outer peripheral side toward the central portion while reducing the volume. Then, the working fluid is sucked from the suction pipe 16 leading to the outside of the closed container 1 and the suction port 17 on the outer periphery of the fixed scroll 12, closed in the compression chamber 15, and then compressed. The refrigerant (hereinafter referred to as a refrigerant) that becomes the working fluid that has reached a predetermined pressure pushes open the discharge lead valve 19 from the discharge port 18 provided at the center of the fixed scroll 12, and the refrigerant that has reached the discharge pressure is released. It passes through the discharge chamber 31 to be discharged, is discharged into the closed container 1, and is finally sent out from the discharge pipe 22 to the outside of the closed container 1.

A pump 25 is provided at the lower end of the shaft 4, and the suction port of the pump 25 is arranged so as to exist in the oil storage unit 20. Since the pump 25 is driven at the same time as the swivel scroll 13, the pump 25 can reliably suck up the oil 6 in the oil storage unit 20 regardless of the pressure condition and the operating speed. As a result, the oil does not run out.

The oil 6 sucked up by the pump 25 is supplied to the compression mechanism 2 through an oil supply hole 26 provided in the shaft 4 in the axial direction. If foreign matter is removed from the oil 6 with an oil filter or the like before or after the oil 6 is sucked up by the pump 25, it is possible to prevent foreign matter from entering the compression mechanism 2 and further improve reliability.

The oil 6 guided by the compression mechanism 2 has substantially the same discharge pressure as the scroll compressor, and also serves as a back pressure source for the swivel scroll 13. Further, a part of the oil 6 enters the fitting portion between the eccentric shaft portion 4a and the swivel scroll 13 and the bearing portion 66 between the shaft 4 and the main bearing member 11 so as to seek an escape place by the supply pressure and its own weight. After lubricating each part, it falls and returns to the oil storage part 20.

FIG. 3 is a view taken along the line CC of FIG. The compression chamber 15 formed by the fixed scroll 12 and the swivel scroll 13 includes an outer compression chamber 15a located outside the lap of the swivel scroll 13 and an inner compression chamber 15b located inside the wrap. The scroll compressor 91 is an asymmetric scroll compressor in which the suction closing volume of the outer compression chamber 15a and the suction closing volume of the inner compression chamber 15b are different volumes. Here, the suction confinement volume is the volume of the compression chamber immediately after confining the refrigerant sucked from the suction port 17. Further, the scroll compressor 91 is an asymmetric scroll compressor in which the suction closing volume of the outer compression chamber 15a is larger than the suction closing volume of the inner compression chamber 15b.

By using an asymmetric scroll compressor, the suction confinement volume of the compressor as a whole increases, so that the space inside the compressor can be used efficiently. Further, since the refrigerant sucked from the suction port 17 can also enter the compression process by confining the outer compression chamber 15a in the vicinity of the suction port 17, the low-pressure low-temperature refrigerant is heated by the compression mechanism 2 and the density of the refrigerant decreases. Can be suppressed.

On the other hand, the difference in the suction confinement volume of each compression chamber affects the volume ratio. The volume ratio is the ratio of the suction confinement volume to the volume of the compression chamber at a certain point in time in the compression step. The volume ratio can be specified for each of the outer compression chamber and the inner compression chamber. Generally, the volume of the compression chamber when the inner compression chamber and the outer compression chamber communicate with the discharge port 18 provided in the central portion of the fixed scroll 12 is substantially equal. When the discharge port 18 is the only discharge path for the refrigerant in the compression chamber, the dischargeable volume ratio of each compression chamber is determined by the suction confinement volume. Here, the dischargeable volume ratio is the ratio of the suction closed volume to the volume of the compression chamber at the time when the compression chamber can be discharged, that is, when the compression chamber communicates with the discharge chamber 31. The dischargeable volume ratio can be specified for each of the outer compression chamber and the inner compression chamber. Since the suction confinement volume of the outer compression chamber 15a is larger than the suction confinement volume of the inner compression chamber 15b, the outer compression chamber 15a has a longer compression step than the inner compression chamber 15b, and the dischargeable volume ratio becomes larger. ..

In the low compression ratio operation, which is the operation in a state where the compression ratio is relatively low, the outer compression chamber 15a is more likely to be in an overcompression state than the inner compression chamber 15b. Here, the compression ratio is the ratio of the discharge pressure to the suction pressure. Further, the outer compression chamber 15a has a larger projected area in the pressing direction of the compression chamber than the inner compression chamber 15b. Therefore, the overcompression of the outer compression chamber 15a tends to increase the force that pushes the swivel scroll 13 away from the fixed scroll 12.

Further, on the lap tip 13c of the swivel scroll 13, the lap height gradually increases from the winding start portion, which is the central portion, to the winding end portion, which is the outer peripheral portion, based on the result of measuring the temperature distribution during operation. The slope shape is provided so as to be. As a result, it is possible to absorb dimensional changes due to thermal expansion and prevent local sliding.

As shown in FIG. 2, the scroll compressor 91 includes a connection path 55-1 and a supply path 55-2 as an oil supply path 55 that guides oil from the oil storage unit 20 to the compression chamber 15. Further, as a refueling path to the compression chamber 15, a passage 13a formed inside the swivel scroll 13 and a recess 12a formed in the lap surface side end plate of the fixed scroll 12 are provided. The passage 13a includes a supply path 55-2.

One opening end 55-2b of the passage 13a is formed at the lap tip 13c and periodically opens into the recess 12a in accordance with the turning motion. Further, the other opening end 55-2a of the passage 13a is always open to the back pressure chamber 29. As a result, the back pressure chamber 29 intermittently communicates only with the inner compression chamber 15b, and does not communicate with the outer compression chamber 15a. Further, by positively supplying oil to the inner compression chamber 15b having a high pressure rise rate, the inner compression chamber 15b-1 (see FIG. 3) formed immediately before was formed next in the compression step. Leakage to the inner compression chamber 15b-2 (see FIG. 3) can be suppressed.

Further, as shown in FIG. 2, on the back surface 13e of the swirl scroll 13, the seal member 78, the high pressure region 30 for holding the refrigerant of the discharge pressure, and the back pressure for holding the refrigerant of a pressure intermediate between the discharge pressure and the suction pressure. It has a room 29. The seal member 78 partitions the inside of the seal member 78 into the high pressure region 30 and the outside of the seal member 78 into the back pressure chamber 29.

At least one of the refueling routes is configured to pass through the back pressure chamber 29. That is, the refueling path 55 is composed of a connection path 55-1 from the high pressure region 30 to the back pressure chamber 29 and a supply path 55-2 from the back pressure chamber 29 to the inner compression chamber 15b. As a result, the swivel scroll 13 is stably pressed against the fixed scroll 12 by the back pressure from the back pressure 13e, the leakage of the refrigerant from the back pressure chamber 29 to the compression chamber 15 can be reduced, and stable operation can be performed. it can.

Further, by using the seal member 78, the pressure in the high pressure region 30 and the back pressure chamber 29 (hereinafter referred to as back pressure) is completely separated, and the pressure application from the back surface 13e of the swivel scroll 13 can be stably controlled.

Further, by providing the connecting path 55-1 from the high pressure region 30 to the back pressure chamber 29, the oil 6 can be supplied to the sliding portion of the rotation restraint mechanism 14 and the thrust sliding portion of the fixed scroll 12 and the swivel scroll 13. ..

Further, by providing the supply path 52 from the back pressure chamber 29 to the inner compression chamber 15b, the amount of oil supplied to the inner compression chamber 15b can be positively increased, and the leakage loss in the inner compression chamber 15b can be suppressed.

Further, one open end 55-1b of the connection path 55-1 is formed on the back surface 13e of the swivel scroll 13, and the seal member 78 is moved back and forth, and the other open end 55-1a is always opened in the high voltage region 30. As a result, intermittent refueling and back pressure adjustment can be realized.

First, intermittent refueling will be described.

FIG. 4 is an explanatory view showing the positional relationship between the seal member and the communication passage with the back pressure chamber due to the turning motion of the scroll compressor. In FIG. 4, the phases are shifted by 90 degrees, and the states are (a) 0 ° to 90 °, (b) 90 ° to 180 °, (c) 180 ° to 270 °, and (d) 270 ° to 360 °. Is shown. That is, FIG. 4 (b) shows a state in which the shaft 4 is rotated 90 degrees from FIG. 4 (a), FIG. 4 (c) is a state in which the shaft 4 is further rotated 90 degrees from FIG. , FIG. 4 (c) shows a state of being further rotated by 90 degrees, and FIG. 4 (a) shows a state of being further rotated by 90 degrees from FIG. 4 (d).

As shown in FIG. 4, one open end 55-1b of the connecting path 55-1 is located on the back surface 13e of the swivel scroll 13. The back surface 13e of the swivel scroll 13 is partitioned by a seal member 78 into an inner high-pressure region 30 and an outer back pressure chamber 29. In the state of FIG. 4B, since one of the opening ends 55-1b is open to the back pressure chamber 29 which is the outside of the seal member 78, the back pressure chamber 29 and the high pressure region 30 communicate with each other. As a result, the oil 6 is supplied from the high pressure region 30 to the back pressure chamber 29. On the other hand, in the states of FIGS. 4A, 4C, and 4D, the back pressure chamber 29 does not communicate with the high pressure region 30 because the opening end 55-1b is open inside the seal member 78. Therefore, the oil 6 is not supplied from the high pressure region 30 to the back pressure chamber 29.

That is, one open end 55-1b of the connection path 55-1 moves back and forth between the high pressure region 30 and the back pressure chamber 29, and there is a pressure difference between the two open ends 55-1a and 55-1b of the connection path 55-1. The oil 6 is supplied to the back pressure chamber 29 only when it occurs. Thereby, the amount of refueling can be adjusted by the time ratio at which one open end 55-1b moves back and forth between the seal member 78. Therefore, the passage diameter of the connecting path 55-1 can be configured to be 10 times or more the size of the oil filter.

In addition, since there is no risk of foreign matter getting caught in the passage and blocking it, it is possible to maintain good lubrication of the thrust sliding portion and the rotation restraint mechanism 14 at the same time as applying stable back pressure, and high efficiency and high reliability are achieved. realizable.

Although the case where the other opening end 55-1a is always in the high pressure region 30 and one opening end 55-1b moves back and forth between the high pressure region 30 and the back pressure chamber 29 has been described as an example, the other opening end 55- Even when 1a moves back and forth between the high pressure region 30 and the back pressure chamber 29 and one of the opening ends 55-1b is always in the back pressure chamber 29, a pressure difference occurs at both opening ends 55-1a and 55-1b, so that it is intermittent. Refueling can be realized and the same effect can be obtained.

Next, the adjustment of the back pressure will be described.

FIG. 5 is an open state diagram of the passageway with the back pressure chamber and the injection port due to the turning motion of the scroll compressor. FIG. 5 is a view in which the swivel scroll 13 is engaged with the fixed scroll 12 and viewed from the back surface 13e of the swivel scroll 13, and the phases are shifted by 90 degrees. Similar to FIG. 4, FIG. 5 shows (a) 0 ° to 90 °, (b) 90 ° to 180 °, (c) 180 ° to 270 °, and (d) 270 ° to 360 °. That is, FIG. 5 (b) shows a state in which the shaft 4 is rotated 90 degrees from FIG. 5 (a), FIG. 5 (c) is a state in which the shaft 4 is further rotated 90 degrees from FIG. , FIG. 5 (c) shows a state of being further rotated by 90 degrees, and FIG. 5 (a) shows a state of being further rotated by 90 degrees from FIG. 5 (d).

The state shown in FIG. 5A is the position where the outer compression chamber 15a traps the refrigerant, and the state shown in FIG. 5C is the position where the inner compression chamber 15b traps the refrigerant.

In the state shown in FIG. 5A, two outer compression chambers 15a are formed, and the outer compression chamber 15a located on the outer peripheral side is in a low pressure state immediately after confining the refrigerant, and is located on the inner peripheral side. The compression chamber 15a is in an intermediate pressure state. In the state shown in FIG. 5C, the outer compression chamber 15a formed on the inner peripheral side is in a high pressure state before discharge.

In the state shown in FIG. 5C, two inner compression chambers 15b are formed, and the inner compression chamber 15b located on the outer peripheral side is in a low pressure state immediately after confining the refrigerant, and is located on the inner peripheral side. The compression chamber 15b is in an intermediate pressure state. In the state shown in FIG. 5D, the inner compression chamber 15b formed on the inner peripheral side is in a high pressure state before discharge.

First, the action of the back pressure chamber 29 will be described. In the state of FIG. 5D, one opening end 55-2b is open to the recess 12a. Therefore, the inner compression chamber 15b communicates with the back pressure chamber 29. During high compression ratio operation, the oil 6 is supplied from the back pressure chamber 29 to the inner compression chamber 15b through the supply passage 55-2 and the passage 13a.

The recess 12a is provided at a position where one of the open ends 55-2b opens immediately after the inner compression chamber 15b traps the sucked refrigerant (hereinafter, sucked refrigerant) (see FIG. 5D). In other words, the refueling path is provided at a position where the intake refrigerant is opened to the inner compression chamber 15b during the compression step after the suction refrigerant is closed by one end 55-2b. Therefore, the pressure in the back pressure chamber 29 while communicating with the inner compression chamber 15b is substantially equal to the pressure in the inner compression chamber 15b. On the other hand, in the states of FIGS. 5A, 5B, and 5C, one of the opening ends 55-2b is not opened in the recess 12a. Therefore, the oil 6 is not supplied from the back pressure chamber 29 to the inner compression chamber 15b. Also, the pressure in the back pressure chamber 29 is not affected by the inner compression chamber 15b.

Further, as described above, in the state of FIG. 4 (b) corresponding to FIG. 5 (b), the back pressure chamber 29 and the high pressure region 30 communicate with each other. As a result, the oil 6 in the high pressure region 30 is shared with the back pressure chamber 29 during the communication, and the pressure in the back pressure chamber 29 rises.

That is, the back pressure chamber 29 can be adjusted to a pressure state intermediate between the suction pressure and the discharge pressure, and this pressure functions as a pressing force on the swivel scroll.

The scroll compressor 91 is provided with a discharge bypass port 21 in addition to the discharge port 18 as a passage for guiding the refrigerant compressed in the compression chamber 15 to the discharge chamber 31. The discharge bypass port 21 is provided with a reed valve like the discharge port 18. When the pressure in the compression chamber 15 reaches the pressure in the discharge chamber 31, the reed valve is pushed open and the refrigerant is discharged to the discharge chamber 31. When the pressure in the compression chamber 15 is less than the pressure in the discharge chamber 31, the reed valve closes to suppress the backflow of the refrigerant from the discharge chamber 31 to the compression chamber 15.

However, as a condition for the discharge bypass port 21 to realize the above-mentioned function, the compression chamber 15 needs to be present at a position where it communicates with the discharge bypass port 21. The discharge bypass port 21 is a fixed passage provided on the end plate of the fixed scroll 12. The compression chamber 15 moves toward the center while reducing the volume with the compression operation, and the refrigerant of the compression chamber 15 is discharged to the discharge chamber 31 only when the compression chamber 15 advances to a position where it communicates with the discharge port 18 or the discharge bypass port 21. Can be discharged to. The discharge bypass port 21 is provided so that the compression chamber 15 communicates with the discharge chamber 31 before the compression chamber 15 communicates with the discharge chamber 31 by the discharge port 18 in the compression step.

The scroll compressor 91 separately provides the discharge bypass port 21a with which the outer compression chamber 15a communicates and the discharge bypass port 21b with which the inner compression chamber 15b communicates, and shifts the timing of communication.

The discharge bypass port 21a does not communicate with the outer compression chamber 15a in the state of FIG. 5A, and communicates with the outer compression chamber 15a located on the outer peripheral side in the states of FIGS. 5B to 5D. It is provided in. The discharge bypass port 21b does not communicate with the inner compression chamber 15b in the state of FIG. 5D, and communicates with the inner compression chamber 15b located on the outer peripheral side in the states of FIGS. 5A to 5C. It is provided in.

The outer compression chamber 15a completes the suction step at the timing shown in FIG. 5A to confine the outer compression chamber 15a. In FIG. 5B in which the compression step has advanced by 90 °, the outer compression chamber 15a is already in a state of communicating with the discharge bypass port 21a. In this case, the dischargeable volume ratio of the outer compression chamber 15a is determined by the ratio of the suction closing volume of the outer compression chamber 15a to the compression chamber volume at the timing when the outer compression chamber 15a communicates with the discharge bypass port 21a, and substantially discharges. It does not depend on the communication timing with the port 18.

On the other hand, the inner compression chamber 15b completes the suction step at the timing shown in FIG. 5C to confine the inner compression chamber 15b. The inner compression chamber 15b does not communicate with the discharge bypass port 21b in FIG. 5 (d) in which the compression process is advanced by 90 °, and communicates with the discharge bypass port 21b in FIG. 5 (a) in which the compression step is further advanced by 90 °. To do. Further, the inner compression chamber 15b communicates with the back pressure chamber 29 via the supply passage 55-2 and the passage 13a at the timing of FIG. 5D.

Also in this case, the dischargeable volume ratio of the inner compression chamber 15b is determined by the communication timing with the discharge bypass port 21b, and the dischargeable volume ratio of the inner compression chamber 15b with which the back pressure chamber 29 communicates is the volume when the back pressure chamber is closed. The ratio and the dischargeable volume ratio of the outer compression chamber 15a are larger. Here, the volume ratio when the back pressure chamber is closed is when the communication between the back pressure chamber 29 and the inner compression chamber 15b in the middle of compression is completed in the compression chamber on the side where the back pressure chamber 29 communicates, that is, the inner compression chamber 15b. (That is, the timing immediately after FIG. 5D) is the ratio of the suction confinement volume to the volume of the inner compression chamber 15b on the outer peripheral side.

Next, a refrigeration cycle apparatus using the scroll compressor 91 will be described.

FIG. 6 is a refrigeration cycle diagram using a scroll compressor according to an embodiment of the present invention.

As shown in FIG. 6, the refrigerating cycle apparatus using the scroll compressor 91 includes a scroll compressor 91, a condenser 92, an evaporator 93, two decompressors 94a and 94b, an injection pipe 95, and a gas-liquid separator 96. I have. The scroll compressor 91, the condenser 92, the upstream decompressor 94a, the gas-liquid separator 96, and the downstream decompressor 94b are connected in an annular shape by piping. The injection pipe 95 connects the gas-liquid separator 96 and the scroll compressor 91.

The refrigerant condensed by the condenser 92 is decompressed to an intermediate pressure by the decompressor 94a on the upstream side, and flows into the gas-liquid separator 96. The gas-liquid separator 96 separates the gas-phase component (gas refrigerant) and the liquid-phase component (liquid refrigerant) of the intermediate-pressure refrigerant. The intermediate-pressure liquid refrigerant passes through the decompressor 94b on the downstream side, becomes a low-pressure refrigerant, and flows into the evaporator 93.

The liquid refrigerant flowing into the evaporator 93 evaporates by heat exchange and is discharged as a gas refrigerant or a gas refrigerant mixed with a part of the liquid refrigerant. The refrigerant discharged from the evaporator 93 flows into the compression chamber 15 of the scroll compressor 91.

On the other hand, the intermediate pressure gas refrigerant separated by the gas-liquid separator 96 passes through the injection pipe 95 and is injected (injected) into the compression chamber 15 in the scroll compressor 91. The injection pipe 95 may be provided with a closing valve or a decompressor to adjust and stop the injection pressure.

In the compression process of compressing the low-pressure refrigerant flowing from the evaporator 93, the scroll compressor 91 injects the intermediate-pressure refrigerant of the gas-liquid separator 96 into the compression chamber 15, compresses the refrigerant, and discharges the refrigerant as a high-temperature high-pressure refrigerant. It is discharged from 22 to the condenser 92.

The ratio of the gas phase component and the liquid phase component separated by the gas-liquid separator 96 will be described. The larger the pressure difference between the inlet side pressure and the outlet side pressure of the decompressor 94a on the upstream side, the larger the gas phase component. Further, the smaller the degree of supercooling of the refrigerant at the outlet of the condenser 92 or the greater the degree of dryness, the greater the gas phase component.

On the other hand, the amount of the refrigerant sucked by the scroll compressor 91 through the injection pipe 95 increases as the intermediate pressure increases. When the refrigerant is sucked from the injection pipe 95 more than the gas phase component ratio of the refrigerant separated by the gas-liquid separator 96, the gas refrigerant of the gas-liquid separator 96 is depleted and the liquid refrigerant flows into the injection pipe 95.

In order to maximize the capacity of the scroll compressor 91, it is desirable that the gas refrigerant separated in the gas-liquid separator 96 is completely sucked into the scroll compressor 91 from the injection pipe 95. If the equilibrium state is deviated, the liquid refrigerant flows from the injection pipe 95 into the scroll compressor 91. Even when the liquid refrigerant flows in from the injection pipe 95, the scroll compressor 91 needs to be configured to maintain high reliability.

Finally, the configuration of the injection tube connecting portion in the scroll compressor 91 of the present embodiment will be described with reference to FIGS. 7 and 8.

FIG. 7 is a view taken along the line AA of FIG. FIG. 8 is a view taken along the line BB of FIG. 7.

The intermediate pressure flowing from the injection pipe 95 shown in FIG. 1 flows into the intermediate pressure chamber 41 as shown in FIGS. 1, 2, 7, and 8, and opens the check valve 42 provided in the injection port 43. , It is injected into the compression chamber 15 after being closed, and is discharged from the discharge port 18 into the closed container 1 together with the refrigerant sucked from the suction port 17.

The injection port 43 for injecting the intermediate pressure refrigerant is provided so as to penetrate the end plate of the fixed scroll 12. The injection port 43 sequentially opens into the outer compression chamber 15a and the inner compression chamber 15b. The injection port 43 is provided at a position where it opens during the compression process after closing in the outer compression chamber 15a and the inner compression chamber 15b.

The intermediate pressure chamber 41 is formed by a fixed scroll 12 which is a compression chamber partition member, an intermediate pressure plate 44, and an intermediate pressure cover 45. The intermediate pressure chamber 41 and the compression chamber 15 face each other with the fixed scroll 12 interposed therebetween. The intermediate pressure chamber 41 is formed at a position lower than the intermediate pressure chamber inlet 41a into which the intermediate pressure refrigerant flows, the injection port inlet 43a of the injection port 43 for injecting the intermediate pressure refrigerant into the compression chamber 15, and the intermediate pressure chamber inlet 41a. It has a liquid reservoir 41b.

The liquid reservoir 41b is formed on the upper surface of the end plate of the fixed scroll 12.

The intermediate pressure plate 44 is provided with a check valve 42 for preventing the refrigerant from flowing back from the compression chamber 15 to the intermediate pressure chamber 41. In the section where the injection port 43 is open to the compression chamber 15, if the internal pressure of the compression chamber 15 is higher than the intermediate pressure of the injection port 43, the refrigerant flows back from the compression chamber 15 toward the intermediate pressure chamber 41. By providing the check valve 42, the backflow of the refrigerant can be prevented.

The check valve 42 is composed of a reed valve 42a that lifts to the compression chamber 15 side to communicate the compression chamber 15 and the intermediate pressure chamber 41, and only when the internal pressure of the compression chamber 15 is lower than the pressure of the intermediate pressure chamber 41. The intermediate pressure chamber 41 communicates with the compression chamber 15. By using the reed valve 42a, there are few sliding points in the movable part, the sealing property can be maintained for a long period of time, and the flow path area can be easily expanded as needed. If the check valve 42 is not provided or if the check valve 42 is provided in the injection pipe 95, the refrigerant in the compression chamber 15 flows back to the injection pipe 95, and wasteful compression power is consumed. In the present embodiment, the check valve 42 is provided in the intermediate pressure plate 44 close to the compression chamber 15 to suppress the backflow from the compression chamber 15.

The upper surface of the end plate of the fixed scroll 12 is located lower than the intermediate pressure chamber inlet 41a, and a liquid reservoir 41b in which the refrigerant of the liquid phase component is collected is provided on the upper surface of the end plate of the fixed scroll 12. Further, the injection port inlet 43a is provided at a position higher than the height of the intermediate pressure chamber inlet 41a. Therefore, among the intermediate pressure refrigerants, the gas phase component refrigerant is guided to the injection port 43, and the liquid phase component refrigerant accumulated in the liquid reservoir 41b is vaporized on the surface of the fixed scroll 12 in a high temperature state. It is difficult for the liquid phase component refrigerant to flow into the compression chamber 15.

Further, the intermediate pressure chamber 41 and the discharge chamber 31 are provided at adjacent positions via the intermediate pressure plate 44, which promotes vaporization when the refrigerant of the liquid phase component flows into the intermediate pressure chamber 41 and also promotes the vaporization of the discharge chamber. Since the temperature rise of the high-pressure refrigerant of 31 can also be suppressed, the operation can be performed up to a correspondingly higher discharge pressure condition.

The intermediate pressure refrigerant guided to the injection port 43 pushes open the lead valve 42a due to the pressure difference between the injection port 43 and the compression chamber 15, and merges with the low pressure refrigerant sucked from the suction port 17 in the compression chamber 15, but does not check back. The intermediate pressure refrigerant remaining in the injection port 43 between the valve 42 and the compression chamber 15 repeats re-expansion and recompression, which causes a decrease in the efficiency of the compressor 91. Therefore, the thickness of the valve stop 42b that regulates the maximum displacement of the reed valve 42a is changed according to the lift regulation location of the reed valve 42a, so that the volume inside the injection port 43 downstream of the reed valve 42a is reduced.

Further, the reed valve 42a and the valve stop 42b are fixed to the intermediate pressure plate 44 by the bolt 48 which is a fixing member, and the fixing hole of the fixing member 48 provided in the valve stop 42b does not penetrate the valve stop 42b. Since the fixing member 48 is open only on the insertion side, as a result, the fixing member 48 is configured to be open only to the intermediate pressure chamber 41. As a result, it is possible to suppress the leakage of the refrigerant between the intermediate pressure chamber 41 and the compression chamber 15 through the gap of the fixing member 48, and it is possible to improve the injection rate.

The intermediate pressure chamber 41 is set to be equal to or larger than the suction volume of the compression chamber 15 so that the injection amount to the compression chamber 15 can be sufficiently supplied. Here, the suction volume is the volume of the compression chamber 15 at the time when the refrigerant guided from the suction port 17 is closed in the compression chamber 15, that is, at the time when the suction process is completed, and the outer compression chamber 15a and the inner compression chamber 15b. The total volume. In the scroll compressor 91 according to the present embodiment, the intermediate pressure chamber 41 is provided so as to spread on the plane of the end plate of the fixed scroll 12, and the volume is expanded. However, when a part of the oil 6 sealed in the scroll compressor 91 goes out from the scroll compressor 91 together with the discharged refrigerant and returns to the intermediate pressure chamber 41 from the gas-liquid separator 96 through the injection pipe 95. If too much oil 6 remains in the liquid reservoir 41b, there is a problem that the oil 6 in the oil storage section 20 becomes insufficient. Therefore, it is not appropriate that the volume of the intermediate pressure chamber 41 is too large. From this, it is preferable that the volume of the intermediate pressure chamber 41 is equal to or larger than the suction volume of the compression chamber 15 and is 1/2 or less of the oil volume of the enclosed oil 6.

As shown in FIG. 5, the injection port 43 is provided at a position where the first compression chamber 15a and the second compression chamber 15b are sequentially opened. Further, the injection port 43 closes the intake refrigerant as shown in the outer compression chamber 15a or FIG. 5 (a) in the compression stroke after closing the intake refrigerant as shown in FIGS. 5 (b) and 5 (c). The end plate of the fixed scroll 12 is provided through the end plate at a position that opens into the inner compression chamber 15b during the compression stroke after loading.

Here, as shown in FIGS. 1 and 2, the intermediate pressure chamber 41 and the internal space 7 in the closed container 1 and the intermediate pressure chamber 41 in the intermediate pressure cover 45 that separates the discharge chamber 31 and the internal space 7 The thickness of the portion that partitions the internal space 7 is thicker than the thickness of the portion that partitions the discharge chamber 31 and the internal space 7. Specifically, the thickness of the portion that partitions the discharge chamber 31 is about 1.5 to 10 times.

Further, as shown in FIG. 7, the surface area of the intermediate pressure chamber 41 in which the intermediate pressure cover 45 is partitioned from the internal space 7 is limited to be smaller than the surface area of the discharge chamber 31 to suppress the heat exchange amount. Specifically, the intermediate pressure cover 45 is set to 2/3 or less of the area for partitioning the internal space 7 and the discharge chamber 31.

[1-2. motion]
The operation according to this embodiment will be described below.

In the scroll compressor of the present embodiment, the intermediate pressure flowing from the injection pipe 95 flows into the intermediate pressure chamber 41 and is provided in the injection port 43 as shown in FIGS. 1, 2, 7, and 8. The check valve 42 is opened, and the check valve 42 is sequentially injected into the outer compression chamber 15a and the inner compression chamber 15b after being closed, and together with the refrigerant sucked from the suction port 17, the closed container is sealed from the discharge port 18 through the discharge chamber 31 and the discharge refrigerant passage 59. It is discharged into the internal space 7 of 1.

Here, the high-temperature refrigerant discharged from the compression chamber 15 to the discharge chamber 31 flows into the internal space 7 of the closed container 1 through the discharge refrigerant passage 59, and is in a high-temperature state substantially equal to that of the discharge chamber 31. The surface of the intermediate pressure cover 45 on the internal space side is exposed to a high temperature refrigerant. In particular, as in the present embodiment, the inside of the closed container 1 is generally in a high pressure state, and the discharge pipe 22 is installed on the same side as the intermediate pressure chamber 41 with respect to the compression chamber 15, especially at a position sandwiching the intermediate pressure chamber 41. In this case, the refrigerant enters the internal space 7 one after another from the discharge chamber 31 and is discharged from the discharge pipe 22, so that the internal space 7 is in a high temperature and high pressure state substantially equal to the discharge chamber 31, and the intermediate pressure cover 45 is used. The internal space side surface of the is exposed to a high temperature refrigerant. On the other hand, the injection refrigerant in the intermediate pressure chamber 41 is in an intermediate pressure state, and is a refrigerant having a lower temperature than the discharge refrigerant. Therefore, heat exchange is performed between the high-temperature refrigerant in the internal space 7 and the injection refrigerant in the intermediate pressure chamber 41.

However, in the compressor of the present embodiment, the thickness of the intermediate pressure cover 45 that separates the intermediate pressure chamber 41 and the internal space 7 in the closed container 1 is thicker than the thickness of the portion that separates the discharge chamber 31 and the internal space 7. Therefore, it is possible to suppress heat exchange between the high temperature refrigerant in the internal space 7 and the injection refrigerant in the intermediate pressure chamber 41.

Further, in the present embodiment, the surface area of the intermediate pressure chamber 41 in which the intermediate pressure cover 45 partitions the internal space 7 is limited to be smaller than the surface area of the discharge chamber 31, and the amount of heat exchange is also suppressed by this. doing.

That is, the temperature difference ΔT between the injection refrigerant and the discharged refrigerant on both surfaces of the intermediate pressure cover 45, the surface area A of the intermediate pressure chamber 41 in which the intermediate pressure cover 45 is partitioned from the internal space 7, and the heat flux q in the thickness direction of the intermediate pressure cover 45. Then, the thermal resistance is increased by reducing the heat flux or the area which is the denominator of the thermal resistance K = ΔT / (qxA). Incidentally, the thickness of the intermediate pressure cover 45 has the effect of reducing the heat flux.

As a result, heat exchange that occurs between the high-temperature refrigerant in the internal space 7 and the injection refrigerant in the intermediate pressure chamber 41 can be suppressed, and each refrigerant can be maintained in an appropriate temperature state. As a result, it is possible to suppress a decrease in the injection rate due to a decrease in the injection refrigerant density and a decrease in the heating capacity (heating capacity) due to a decrease in the temperature of the refrigerant discharged from the discharge pipe 22, as described in the background art.

The thickness referred to here means the average thickness of the region where the intermediate pressure cover 45 is partitioned from the internal space 7, and when a plurality of members are combined and configured, it means the total thickness thereof.

Further, it is desirable that the thickness of the intermediate pressure cover 45 is about 1.5 to 10 times thicker than the thickness of the portion that partitions the discharge chamber 31 and the internal space 7.

Further, the surface area of the intermediate pressure chamber 41 in which the intermediate pressure cover 45 partitions the internal space 7 is preferably 2/3 or less of the area in which the intermediate pressure cover 45 partitions the internal space 7 and the discharge chamber 31.

[1-3. Effect, etc.]
As described above, in the present embodiment, the compressor has a compression mechanism unit that sucks the refrigerant in the low pressure state into the closed container and compresses it into the high pressure state, and from the compression chamber in the compression mechanism portion to the discharge chamber. In a compressor in which the refrigerant discharged to the outside is sent out of the closed container from the discharge pipe via the internal space around the compression mechanism, the compressor is provided with a refrigerant in an intermediate pressure state between low pressure and high pressure in the closed container. It has an injection pipe for drawing in from the outside of the compressor, and both the intermediate pressure chamber and the discharge chamber into which the refrigerant guided from the injection pipe flows are provided adjacent to the compression chamber, and the internal space, the intermediate pressure chamber, and the discharge chamber are further divided. The partition member is configured such that the second thermal resistance, which is the thermal resistance between the internal space and the intermediate pressure chamber, is larger than the first thermal resistance, which is the thermal resistance between the internal space and the discharge chamber. As a result, it is possible to suppress the decrease in the discharge temperature due to the injection refrigerant and the heat reception of the injection refrigerant in the intermediate pressure chamber, and to guide the injection refrigerant to the compression chamber while maintaining a high density. Therefore, it is possible to provide a compressor with a high-performance and high-efficiency injection mechanism.

In the present embodiment, the refueling path is used as the connecting passage between the compression chamber and the back pressure chamber, but the same effect can be obtained by providing a path independent of the refueling path. Further, the back pressure chamber is not limited to the back side of the swivel scroll, and may be provided on the back side of the fixed scroll and the fixed scroll may be pressed against the swivel scroll.

Further, in the present embodiment, a compressor with a scroll type injection mechanism is used, but the same effect can be obtained by using other compression methods such as a rotary method, a reciprocating method, and a screw method.

(Other embodiments)
As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technique in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. have been made. It is also possible to combine the components described in the first embodiment to form a new embodiment.

Therefore, other embodiments will be illustrated below.

In the first embodiment, the thickness of the intermediate pressure cover 45, which is a partition member for partitioning the intermediate pressure chamber 41 and the internal space 7, is made thicker than the thickness of the portion for partitioning the discharge chamber 31 and the internal space 7, and the intermediate pressure cover is thickened. It has been explained that the surface area of the intermediate pressure chamber 41 that is partitioned from the internal space 7 of the 45 is limited to be smaller than the surface area of the discharge chamber 31 to suppress the amount of heat exchange.

The intermediate pressure cover 45 serving as the partition member may have a configuration that efficiently suppresses heat exchange generated between the high temperature refrigerant in the internal space 7 and the injection refrigerant in the intermediate pressure chamber 41.

Therefore, for example, as shown in FIG. 9, the low thermal conductive material 46, which is a material having a lower thermal conductivity than the intermediate pressure cover 45, is on the surface of the portion of the intermediate pressure cover 45 that partitions the intermediate pressure chamber 41 and the internal space 7. May be fixed by pasting or fastening. In this case, the heat insulating performance of only the intermediate pressure chamber 41 that requires heat insulation is improved, and heat exchange between the refrigerants can be economically suppressed. In FIG. 9, the low heat conductive material 46 is provided on the surface on the internal space side, but the same effect can be obtained even if it is provided on the intermediate pressure chamber 41 side. Further, as the material of the low thermal conductive material 46, a resin material such as polyester or silicon, a sintered material, a porous material or the like is preferable from the viewpoint of thermal conductivity and chemical stability.

Alternatively, as shown in FIG. 10, the intermediate pressure chamber 41 and the internal space 7 may be partitioned by the intermediate pressure cover 45, and the discharge chamber 31 and the internal space 7 may be partitioned by the discharge chamber cover 47 different from the intermediate pressure cover 45. Good. In this case, the intermediate pressure cover 45 can select a material, thickness, and shape different from those of the discharge chamber cover 47, and the degree of freedom in design is improved.

In each embodiment of the present embodiment, the refueling path 55 is used as a connecting passage between the compression chamber 15 and the back pressure chamber 29, but the same effect can be obtained by providing a route independent of the refueling path 55. .. Further, the back pressure chamber 29 is not limited to the back side of the swivel scroll 13, but may be provided on the back side of the fixed scroll 12 and the fixed scroll 12 may be pressed against the swivel scroll.

Further, in the present embodiment, a compressor with a scroll type injection mechanism is used, but the same effect can be obtained by using other compression methods such as a rotary method, a reciprocating method, and a screw method.

The present invention can be applied to a compressor with an injection mechanism that suppresses a decrease in discharge temperature due to an injection working fluid and heat reception of the injection working fluid in an intermediate pressure chamber. Then, it is useful for a refrigerating device such as an air conditioner or a refrigerator, or a heat pump type hot water supply device.

1 Airtight container 2 Compression mechanism 3 Motor part 4 Shaft 4a Eccentric shaft part 6 Oil 7 Internal space 11 Main bearing member 12 Fixed scroll 12a Recess 13 Swing scroll 13c Wrap tip 13e Back 14 Rotation restraint mechanism 15 Compression chamber 15a Outside compression chamber 1 compression chamber)
15b Inner compression chamber (second compression chamber)
16 Suction pipe 17 Suction port 18 Discharge port 19 Discharge lead valve 20 Oil storage section 21, 21a, 21b Discharge bypass port 22 Discharge pipe 25 Pump 26 Oil supply hole 29 Back pressure chamber 30 High pressure region 31 Discharge chamber 41 Intermediate pressure chamber 41a Intermediate pressure Chamber inlet 41b Liquid reservoir 42 Check valve 42a Reed valve 42b Valve stop 43 Injection port 43a Injection port inlet 44 Intermediate pressure plate (intermediate pressure chamber partition member)
45 Intermediate pressure cover (partition member)
46 Low heat conductive material 47 Discharge chamber cover 48 Fixing member (bolt)
55 Refueling path 55-1 Connection path 55-1a The other open end (high pressure region side)
55-1b One end (back pressure chamber side)
55-2 Supply path 55-2a The other end (back pressure chamber side)
55-2b One end (compression chamber side)
59 Discharge refrigerant passage 66 Bearing part 78 Seal member 91 Compressor (scroll compressor)
92 Condenser 93 Evaporator 94 Decompressor 95 Injection tube 96 Gas-liquid separator

Claims (8)

The inside of the closed container has a compression mechanism unit that sucks the working fluid in the low pressure state and compresses it into the high pressure state, and the working fluid discharged from the compression chamber in the compression mechanism unit to the discharge chamber is the compression mechanism unit. In the compressor that is sent out of the closed container from the discharge pipe via the internal space around the
The compressor has an injection pipe for drawing a working fluid in an intermediate pressure state between low pressure and high pressure from the outside of the closed container.
The intermediate pressure chamber into which the working fluid guided from the injection pipe flows and the discharge chamber are both provided adjacent to the compression chamber, and the partition member for partitioning the internal space, the intermediate pressure chamber, and the discharge chamber is A compressor with an injection mechanism, characterized in that the second thermal resistance, which is the thermal resistance between the internal space and the intermediate pressure chamber, is made larger than the first thermal resistance, which is the thermal resistance between the internal space and the discharge chamber. Machine. The compressor with an injection mechanism according to claim 1, wherein the partition member has a thickness between the internal space and the intermediate pressure chamber larger than the thickness between the internal space and the discharge chamber. The compression with an injection mechanism according to claim 1 or 2, wherein the partition member has an area for partitioning the internal space and the intermediate pressure chamber smaller than an area for partitioning the internal space and the discharge chamber. Machine. Claims 1 to 3 are characterized in that the portion of the partition member that partitions the internal space and the intermediate pressure chamber is made of a material having a lower thermal conductivity than the portion that partitions the internal space and the discharge chamber. The compressor with an injection mechanism according to any one of the above items. Any one of claims 1 to 4, wherein at least a part of the surface of the portion that partitions the internal space of the partition member and the intermediate pressure chamber is covered with a material having a thermal conductivity lower than that of the partition member. Compressor with injection mechanism described in. The compressor with an injection mechanism according to any one of claims 1 to 5, wherein the intermediate pressure chamber and the discharge chamber are provided on the discharge pipe side with reference to the compression chamber. The compressor with an injection mechanism according to any one of claims 1 to 6, wherein the intermediate pressure chamber and the discharge chamber are separated from the internal space by at least one or more different partition members. The method according to any one of claims 1 to 7, wherein the inside of the closed container surrounding the compression mechanism portion is filled with the internal space substantially in a discharge pressure state, except for the compression mechanism portion. The compressor with an injection mechanism described in item 1.

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