JP4455546B2 - High pressure shell type compressor and refrigeration system - Google Patents

Description

  The present invention relates to a refrigeration apparatus, and more particularly to a refrigeration apparatus that includes a high-pressure shell type compressor and adjusts the oil level of the lubricating oil.

A compressor in a conventional refrigeration apparatus is provided with a compression unit at the top in the shell, and a drive unit such as a motor for driving the compression unit at the bottom, and stores the lubricating oil of the compression unit and the drive unit at the bottom. A storage part is provided.
Further, the lower end portion of the main shaft of the driving unit is immersed in the lubricating oil, and the lubricating oil is pumped up by the pump mechanism formed in the lower end portion of the main shaft and the oil passage formed in the main shaft, and the compression unit and the driving unit To be supplied.

FIG. 13 is a longitudinal sectional view of a low pressure shell type compressor.
In FIG. 13, 1100 is a shell of a low-pressure shell type compressor, 1101 is a suction pipe provided on the side of the shell 1100, 1102 is a discharge pipe provided on the top of the shell 1100, and 1103 is in the shell of the discharge pipe 1102 A compression mechanism represented by a scroll connected to the end, 1104 is a rotating shaft extending downward from the vicinity of the center of the compression mechanism 1103, 1105 is a rotor of a compressor motor formed around the rotating shaft 1104, 1106 Is a stator provided on the inner surface of the shell 1100 so as to surround the rotor 1106, 1107 is an oil circulation pipe that penetrates the rotating shaft 1104, 1108 is oil that stays in the lower portion of the shell 1100, and 1109 is in the lower portion of the rotating shaft 1104 An oil pump is provided.

Next, the refrigerant and oil flows in the low-pressure shell type compressor of FIG. 13 will be described.
First, low-pressure gas refrigerant and a small amount of oil are sucked into the shell 1100 from the suction pipe 1101. The sucked gas refrigerant flows into the compression mechanism 1103, is compressed by the rotation of the rotor 1105, becomes a high-pressure gas refrigerant, and is discharged outside the compressor through the discharge pipe 1102. Since the inside of the shell 1100 is filled with the low-pressure gas refrigerant, most of the inside is a low-pressure space.

  On the other hand, most of the oil sucked from the suction pipe 1101 falls in the process of filling the shell 1100 together with the sucked-in low-pressure gas refrigerant, or in the process of being compressed by the compression mechanism 1103, It stays in the lower part of the shell 1100. A part of the oil is discharged from the discharge pipe 1102 to the outside of the compressor together with the gas refrigerant.

  The oil 1108 staying in the lower part of the shell 1100 is sucked up by the oil pump 1109 and is carried to the drive portion of the compression mechanism 1103 through the oil circulation pipe 1107. Most of the oil supplied to the drive part falls again to the lower part of the shell 1100, but a part of the oil enters the compression mechanism 1103 and is discharged together with the gas refrigerant from the discharge pipe 1102 to the outside of the compressor.

  In such a low-pressure shell type compressor, the drive part of the compression mechanism 1103 becomes a low-pressure part, and the oil retention part below the shell 1100 also becomes the same low-pressure part, so the drive of the compression mechanism 1103 from the oil retention part below the shell 1100 In order to raise the oil to the part, it is necessary to give the oil a pressure equal to or higher than the liquid column pressure of the oil from the oil retention part at the lower part of the shell 1100 to the drive part of the compression mechanism 1103. Therefore, as a means for applying pressure to the oil, an oil pump 1109 constituted by a mechanism using a centrifugal force generated by the rotation of the rotating shaft 1104 or a gear-type pump mechanism is generally used.

FIG. 14 is a longitudinal sectional view of a high-pressure shell type compressor.
In FIG. 14, 1200 is a shell of a high-pressure shell type compressor, 1201 is a suction pipe provided on the side of the shell 1200, 1202 is a compression mechanism such as a scroll connected to the inner end of the shell of the suction pipe, and 1203 is a compression mechanism. A discharge unit 1202 is provided at the top of the mechanism 1202 and discharges compressed refrigerant gas into the shell 1200. 1204 is a discharge pipe provided on the side of the shell 1200 at a position below the compression mechanism 1203. 1205 is a compression mechanism. A rotating shaft extending downward from the center of 1202, 1206 is a rotor of a compressor motor formed around the rotating shaft 1205, 1207 is a stator provided on the inner surface of the shell 1100 so as to surround the rotor 1206. 1208 is an oil circulation pipe that penetrates the rotating shaft 1205, 1209 is oil that stays in the lower part of the shell 1200, 1210 Than the compression mechanism 202 is a connection hole for connecting the upper space and a lower space.

Next, the flow of refrigerant and oil in the high-pressure shell type compressor of FIG. 14 will be described.
First, a low-pressure gas refrigerant and a small amount of oil are sucked into the shell 1200 from the suction pipe 1201. The sucked gas refrigerant directly flows into the compression mechanism 1202, is compressed by the rotation of the rotor 1206, becomes a high-pressure gas refrigerant, and is discharged into the shell 1200 through the discharge unit 1203. The high-pressure gas refrigerant discharged into the shell 1200 passes through the communication pipe 1210, moves downward, and is discharged from the discharge pipe 1204 to the outside of the compressor. Since the shell 200 is filled with high-pressure gas refrigerant, most of the space is a high-pressure space.

  On the other hand, most of the oil sucked from the suction pipe 1201 falls in the process of being compressed by the compression mechanism 202 together with the sucked-in low-pressure gas refrigerant, and in the process of filling the shell 1200, so that the shell It stays at the bottom of 1200. Part of the oil is discharged from the discharge pipe 1204 to the outside of the compressor together with the high-pressure gas refrigerant.

  The oil 1209 staying in the lower part of the shell 1200 moves up the oil circulation pipe 1208 and is carried to the drive portion of the compression mechanism 1202. Most of the oil carried to this drive part falls again and stays in the lower part of the shell 1200, but a part of the oil enters the compression mechanism 1202 and is sucked from the suction pipe 1201 and a small amount of gas refrigerant. The oil is combined and compressed.

  In the high pressure shell type compressor, the drive part of the compression mechanism 1202 is a low pressure part or an intermediate pressure part between the high pressure and the low pressure, and the oil retention part below the shell 1200 is a high pressure part. Even if the mechanism 1209 does not use an oil pump or the like, the oil circulation pipe 1208 is raised and conveyed to the drive unit of the compression mechanism 1202.

Since the compressor in the conventional refrigeration apparatus is configured as described above, when the oil level of the lubricating oil in the storage unit rises and reaches the state where the rotor of the driving unit is immersed in the lubricating oil, the lubricating oil This becomes a resistance against the rotation of the rotor, and there is a problem that the power consumption of the drive unit increases.
In general, the rate at which the oil sucked into the compressor is discharged outside the compressor without staying in the lower part of the shell increases as the rotational speed of the rotary shaft increases and the amount of oil sucked increases. To do.

  In the high-pressure shell type compressor, when the amount of oil accumulated in the lower portion of the shell 1200 increases and the liquid level of the oil 1209 comes into contact with the rotor 1206, the oil 1209 is wound up, and the rolled up oil is discharged from the discharge pipe 1204 to the compressor. The phenomenon of being discharged outside occurs. As described above, when the amount of oil increases, the oil level and the rotor come into contact with each other. As a result, a load due to the resistance of the oil is generated in the rotation of the rotor.

  In addition, an oil separator is connected to the discharge pipe of the compressor, and this oil separator separates the oil discharged from the compressor and returns it to the compressor to prevent the oil from flowing to the heat exchanger of the refrigeration cycle. It is generally done. However, if the amount of oil discharged from the compressor is excessive, the oil separator cannot sufficiently separate the oil, and the concentration of oil relative to the circulating refrigerant will increase, reducing the heat transfer characteristics of the refrigerant, There is a problem that the performance decreases.

  In addition, oil has a higher viscosity than refrigerant and requires more energy than refrigerant to circulate in the refrigeration cycle, so the rate at which oil is discharged out of the compressor increases. There is a problem that the input loss of the machine increases.

  In addition, the phenomenon of oil being rolled up by the contact between the oil staying at the bottom of the compressor shell and the rotor occurs even in the case of the low pressure shell type compressor, but in the low pressure shell type compressor, the contact between the oil and the rotor. Since there is a compression mechanism on the downstream side of the part, oil is separated by the compression mechanism and falls down, so compared with a high-pressure shell type compressor that has a compression mechanism on the upstream side of the contact part between the oil and the rotor. Less oil is required.

  Also, in the low-pressure shell type compressor, the oil supply from the oil accumulation part in the shell to the drive part of the compression mechanism is performed by an oil pump that is driven in conjunction with the rotation of the rotary shaft, so the rotational speed of the rotary shaft increases. If it does, the oil discharge amount of a low pressure shell type compressor will also increase, and if the rotation speed of a rotating shaft reduces, the oil discharge amount of a low pressure shell type compressor will also decrease. Therefore, in order to keep the oil amount in the low-pressure shell type compressor within an appropriate range, the oil return amount corresponding to the rotational speed of the rotating shaft, that is, the refrigerant circulation amount may be set.

  Therefore, in the conventional refrigeration cycle using the low-pressure shell type compressor, oil is returned to the low-pressure shell type compressor using the differential pressure due to the pressure drop that occurs when the refrigerant passes through the piping, and the amount of refrigerant circulation is If the differential pressure due to the pressure drop that occurs when the refrigerant passes through the pipe increases and the pressure difference increases, the oil return also increases, and the refrigerant circulation quantity decreases and the differential pressure due to the pressure drop that occurs when the refrigerant passes through the pipe The amount of oil returned is also reduced as the engine oil becomes smaller, so that the amount of oil in the low-pressure shell type compressor is maintained in an appropriate range regardless of the amount of refrigerant circulation.

  However, in a high-pressure shell type compressor, the oil supply from the oil retention part in the shell to the drive part of the compression mechanism is performed using the differential pressure between the oil retention part and the drive part of the compression mechanism. The oil discharge rate of the compressor increases if the differential pressure between the low pressure part and the low pressure part increases, and the oil discharge amount of the compressor decreases if the differential pressure between the high pressure part and the low pressure part in the compressor decreases. When operating a high-pressure shell type compressor with a low-pressure shell type oil return system, if the differential pressure between the high-pressure part and the low-pressure part is large and the refrigerant circulation rate is small, the amount of oil taken out from the compressor is large. Since the amount of oil returned to the compressor is small, the amount of oil in the compressor becomes too small, and no oil is supplied to the drive part of the compressor rotation mechanism, so the drive part of the rotation mechanism becomes poorly lubricated, and the high pressure part and low pressure part When the differential pressure is small and the refrigerant circulation rate is large The amount of oil in the compressor for a large oil return of the compressor oil takeout amount is small even though the compressor becomes excessive, the oil rate in the refrigerant cycle becomes higher.

  In addition, when multiple compressors are installed and operated in parallel, when the compressor is a low-pressure shell type, the capacities are reduced from a compressor with a small capacity and a high internal pressure by connecting the shells with an oil equalizing pipe. By moving the lubricating oil to a compressor with a large internal pressure and balancing the oil level, some of the compressor will accumulate excessive lubricating oil, and the amount of oil in other compressors will decrease and the lubricating oil will be depleted. However, in a high-pressure shell type compressor, the internal pressure of a large-capacity compressor tends to be high. Lubricating oil moves from a large compressor to a small-capacity compressor, and there is a problem that it is not possible to prevent excessive accumulation of lubricating oil in some compressors and depletion of lubricating oil in other compressors. It was.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a compressor and a refrigeration apparatus that can prevent the oil level of the lubricating oil from exceeding a predetermined position.
In other words, a first object of the present invention is to provide a compressor and a refrigeration cycle in which oil staying in the lower part of the shell can be prevented from coming into contact with the rotor.

  Furthermore, the second object is to provide a refrigeration cycle capable of efficiently returning oil flowing out of the compressor from the discharge pipe into the compressor.

  In addition, even when multiple compressors are installed and operated in parallel, the oil level of the lubricating oil of the compressor can be kept from exceeding a predetermined position, resulting in excessive oil deviation between the compressors. And a third object is to provide a refrigeration apparatus that can reduce the amount of oil necessary for preventing depletion.

  In one aspect of the present invention, in the high-pressure surrogate compressor according to the present invention, the oil that drains the oil remaining in the shell to the outside at a position that is higher than the opening at the lower end of the oil circulation pipe and lower than the lower end of the rotor. An outflow hole was provided.

  In another aspect of the present invention, a refrigeration apparatus according to the present invention is compressed by a gas refrigerant suction section, a compression section that compresses the sucked gas refrigerant, and a drive section that drives the compression section. A refrigeration cycle including a high-pressure shell type compressor having a discharge part for discharging the gas refrigerant, a storage part for storing lubricating oil for the compression part and the drive part, and a discharge pipe and a suction part connected to the discharge part The refrigeration apparatus including the refrigerant circuit to be configured includes a device that guides surplus oil to the discharge pipe when the oil level of the reservoir exceeds a predetermined position.

  In another aspect of the present invention, the refrigeration apparatus according to the present invention is preferably a device that guides surplus oil to the discharge pipe, one end of which opens to a predetermined position on the oil surface of the reservoir of the compressor, An oil drain pipe whose end is connected to the discharge pipe through the outside of the compressor is provided.

  In another aspect of the present invention, the refrigeration apparatus according to the present invention is preferably a device that guides surplus oil to the discharge pipe, one end of which opens to a predetermined position on the oil surface of the reservoir of the compressor, An oil drain pipe whose end opens from the inside of the compressor through the discharge section into the discharge pipe is provided.

  In another aspect of the present invention, in the refrigeration apparatus according to the present invention, a shell, a compression mechanism built in the shell, a rotation shaft for driving the compression mechanism, a rotor and a motor including a stator, It is higher than the opening at the lower end of the oil distribution pipe of the high-pressure shell type compressor having an oil distribution pipe extending from the lower part of the shell toward the built-in compression mechanism and sending the oil staying in the lower part of the shell to the compression mechanism, An oil outflow hole provided at a position lower than the lower end of the rotor disposed around the rotating shaft, an oil inflow hole provided in the discharge pipe, and an oil bypass pipe connecting the oil outflow hole and the oil inflow hole; Equipped with.

  In another aspect of the present invention, preferably, a throttle portion is further provided on the high pressure shell type compressor side than the oil inflow hole of the discharge pipe.

  In another aspect of the present invention, in the refrigeration apparatus according to the present invention, the refrigeration apparatus is positioned higher than the opening at the lower end of the oil circulation pipe of the high-pressure shell type compressor and lower than the lower end of the rotor disposed around the rotating shaft. An oil outflow hole provided, an oil inflow hole provided in the oil return pipe, and an oil bypass pipe connecting the oil outflow hole and the oil outflow hole were provided.

  In another aspect of the present invention, preferably, a throttle portion is further provided closer to the oil separator than the oil inflow hole of the oil return pipe.

  In another aspect of the present invention, preferably, the height position of the oil outflow hole is equal to or higher than the height position of the oil inflow hole.

  In another aspect of the present invention, preferably, a pump for sending oil from the oil outflow hole to the oil inflow hole is further provided in the oil bypass pipe.

  In another aspect of the present invention, a refrigeration apparatus according to the present invention is compressed by a gas refrigerant suction section, a compression section that compresses the sucked gas refrigerant, and a drive section that drives the compression section. A refrigeration cycle comprising a high-pressure shell type compressor having a discharge part for discharging the gas refrigerant, a storage part for storing lubricating oil for the compression part and the drive part, and an accumulator and discharge part connected to the suction part In the refrigeration apparatus provided with the refrigerant circuit, a device for guiding excess oil to the accumulator when the oil level of the reservoir exceeds a predetermined position is provided.

  In another aspect of the present invention, the refrigeration apparatus according to the present invention is preferably a device that guides surplus oil to an accumulator, one end of which opens at a predetermined position on the oil surface of the reservoir of the compressor, and the other end Is provided with an oil drain pipe connected to an accumulator.

  In another aspect of the present invention, in the refrigeration apparatus according to the present invention, preferably, the predetermined position of the oil surface of the storage unit is a position where the rotor of the drive unit is not immersed in the lubricating oil.

  In another aspect of the present invention, in the refrigeration apparatus according to the present invention, the first oil return means for sending the oil in the accumulator to the lowermost part of the U-shaped pipe, and the first oil return means. And a second oil returning means for sending the oil in the accumulator into the U-shaped pipe at a higher position, and the amount of oil sent from the first oil returning means to the U-shaped pipe is discharged from the high-pressure shell type compressor. The amount of oil that is smaller than the amount of oil discharged to the pipe and is sent from both the first oil return means and the second oil return means to the U-shaped pipe is oil discharged from the high-pressure shell type compressor to the discharge pipe. Greater than the amount.

  In another aspect of the present invention, preferably, the accumulator further includes a first chamber in which the U-shaped tube is disposed and a second gas chamber in which the refrigerant gas discharge port is provided by a partition plate provided in the vertical direction. Furthermore, the end of the oil return pipe is provided at the lower part of the first room, and the refrigerant gas in the first room is sent to the second room at the upper part of the partition plate. A communication hole was provided.

  In another aspect of the present invention, the refrigeration apparatus according to the present invention is preferably configured such that a plurality of compressors are installed and can be operated in parallel.

  In another aspect of the present invention, the refrigeration apparatus according to the present invention is preferably configured such that the apparatus that guides surplus oil to the discharge pipe or the accumulator has a stagnant oil amount in the oil storage section among a plurality of compressors. The compressor is provided only in the compressor that is likely to increase.

  In the high-pressure surreal compressor according to the present invention, an oil outflow hole for discharging oil staying in the shell to the outside is provided at a position higher than the opening at the lower end of the oil circulation pipe and lower than the lower end of the rotor. Thereby, the high pressure surreal compressor which can keep the oil level of lubricating oil from exceeding a predetermined position can be obtained.

  A refrigerating apparatus according to the present invention includes a gas refrigerant suction unit, a compression unit that compresses the sucked gas refrigerant, a drive unit that drives the compression unit, a discharge unit that discharges the compressed gas refrigerant, and a compression unit In a refrigeration apparatus including a high-pressure shell type compressor having a reservoir for storing lubricating oil for a part and a drive unit, and a refrigerant circuit that constitutes a refrigeration cycle including a discharge pipe and a suction part connected to the discharge part, When the oil level of the storage part exceeds a predetermined position, it is equipped with a device that guides excess oil to the discharge pipe, and since the oil of a predetermined level or more does not stay in the compressor, the required oil amount can be reduced. .

Further, in the refrigeration apparatus according to the present invention, an oil outflow hole provided at a position that is higher than the opening at the lower end of the oil circulation pipe of the high-pressure shell type compressor and lower than the lower end of the rotor disposed around the rotating shaft; And an oil inflow hole provided in the discharge pipe, and an oil bypass pipe for connecting the oil outflow hole and the oil inflow hole.
Thereby, the oil level and the rotor do not come into contact with each other, and the rotation of the rotor can be prevented from receiving a load due to the oil.

  Furthermore, since the throttle portion is provided on the high-pressure shell type compressor side of the oil inlet hole of the discharge pipe, the oil can be reliably bypassed from the oil outlet hole to the oil inlet hole.

  Further, in the refrigeration apparatus according to the present invention, an oil outflow hole provided at a position that is higher than the opening at the lower end of the oil circulation pipe of the high-pressure shell type compressor and lower than the lower end of the rotor disposed around the rotating shaft; Since the oil inflow hole provided in the oil return pipe and the oil bypass pipe for connecting the oil outflow hole and the oil outflow hole are provided, a large amount of oil can be prevented from circulating.

  Furthermore, since the throttle portion is provided on the oil separator side of the oil return hole of the oil return pipe, oil can be reliably bypassed from the oil outflow hole to the oil inflow hole.

  In addition, since the height of the oil outflow hole is equal to or higher than the height of the oil inflow hole, it is necessary to consider the effect of the oil column pressure due to the rise of the oil bypass pipe from the oil outflow hole to the oil inflow hole. Disappears.

  Furthermore, since the oil bypass pipe is provided with a pump for sending oil from the oil outflow hole to the oil inflow hole, the oil can be reliably bypassed from the oil outflow hole to the oil inflow hole.

  A refrigerating apparatus according to the present invention includes a gas refrigerant suction unit, a compression unit that compresses the sucked gas refrigerant, a drive unit that drives the compression unit, a discharge unit that discharges the compressed gas refrigerant, and a compression unit In a refrigeration apparatus including a high-pressure shell type compressor having a reservoir for storing lubricating oil for a part and a drive unit, and a refrigerant circuit that constitutes a refrigeration cycle including a discharge pipe and a suction part connected to the discharge part, When the oil level of the reservoir exceeds a predetermined position, a device is provided that guides surplus oil to the accumulator. Since the oil of a predetermined level or more does not stay in the compressor, the required oil amount can be reduced.

  Further, in the refrigeration apparatus according to the present invention, the first oil return means for sending the oil in the accumulator into the U-shaped pipe at the bottom of the U-shaped pipe, and the oil in the accumulator at a position higher than the first oil return means. A second oil return means for feeding into the U-shaped pipe, and the amount of oil sent from the first oil return means to the U-shaped pipe is greater than the amount of oil discharged from the high-pressure shell type compressor to the discharge pipe. The amount of oil that is small and sent from both the first oil return means and the second oil return means to the U-shaped pipe is larger than the amount of oil discharged from the high-pressure shell type compressor to the discharge pipe. Therefore, it is possible to prevent input loss due to contact between the oil level and the rotor, and to prevent a large amount of oil from circulating.

  Furthermore, the accumulator is divided into a first room in which the U-shaped tube is arranged and a second room in which the refrigerant gas discharge port is provided by a partition plate provided in the vertical direction. Since the end of the oil return pipe is opened at the bottom of the first chamber, and the upper part of the partition plate is provided with a communication hole through which the refrigerant gas in the first chamber can be sent to the second chamber, the accumulator Compared to the case where it is not divided, it is possible to immediately cope with subtle changes in the oil amount.

In the refrigeration apparatus according to the present invention, since the plurality of compressors are operated in parallel and the surplus oil is discharged to the discharge pipe or the accumulator, the surplus oil of the compressor whose lubricating oil exceeds a predetermined level is directly received. The accumulator is returned to the accumulator through the refrigerant circuit from the discharge pipe and a sufficient amount of oil is secured in the accumulator, so that other compressors are depleted of lubricating oil by returning from the accumulator. Can be prevented.
In addition, the amount of oil necessary for preventing depletion can also be reduced.

  In order to describe the high-pressure shell type compressor and the refrigeration apparatus of the present invention in more detail, it will be described with reference to the accompanying drawings.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a refrigeration cycle in Embodiment 1 of the present invention.
In FIG. 1, the refrigeration cycle connects the high pressure shell type compressor 1, the discharge pipe 2 of the high pressure shell type compressor 1, the oil separator 3, the four-way valve 4, the outdoor heat exchanger 5, and the outdoor unit and the indoor unit. Liquid pipe 6, indoor unit expansion device 7, indoor heat exchanger 8, gas pipe 9 connecting the indoor unit and the outdoor unit, accumulator 10, U-shaped pipe 11 provided in the accumulator 10, high-pressure shell type compressor 1 Mainly constructed by sequentially connecting the suction pipes 12. As the high-pressure shell type compressor 1, the one described with reference to FIG. 14 is applied. The expansion device 7 and the indoor heat exchanger 8 are installed in the indoor unit, and the high-pressure shell type compressor 1, the oil separator 3, the four-way valve 4, the outdoor heat exchanger 5, the accumulator 10, and the like are installed in the outdoor unit that is a refrigeration device. Has been. An oil return hole 13 is formed in the lowermost portion of the U-shaped tube 11. Reference numeral 14 denotes an oil return pipe having one open end connected to the oil separator 3 and the other open end inserted into the bottom of the accumulator 10.

  Further, the high-pressure shell type compressor 1 is below the rotor, which is the rotating part of the compressor motor, and is located on the lower side of the shell of the oil circulation pipe that connects the drive part of the high-pressure shell type compressor and the oil retention part at the lower part of the shell. An oil outlet 15 opened at a position above the oil suction port located at the nozzle and an oil inlet 16 opened at the discharge pipe 2 are connected by an oil bypass pipe 17.

  This will be explained with reference to the high-pressure shell type compressor in FIG. 14. The oil outlet 15 in FIG. 1 is located at a position below the rotor 1207 which is a rotating part of the compressor motor in FIG. In addition, the oil circulation pipe 1208 that connects the compression mechanism 1202 and the oil retaining portion below the shell 1200 is opened at a position above the oil suction port that is located on the shell lower side.

Next, the operation during cooling operation in the refrigeration cycle of FIG. 1 will be described.
The mixed gas of high-temperature and high-pressure gas refrigerant and oil discharged from the high-pressure shell type compressor 1 flows into the oil separator 3 through the discharge pipe 2, and is separated into gas refrigerant and oil by the oil separator 3. The separated oil flows into the accumulator 10 through the oil return pipe 14, and the separated gas refrigerant flows into the outdoor heat exchanger 5 through the four-way valve 4. The high-temperature and high-pressure gas refrigerant that has flowed into the outdoor heat exchanger 5 condenses in the outdoor heat exchanger 5, becomes medium-temperature and high-pressure liquid refrigerant, flows into the indoor unit through the liquid pipe 6, and is throttled by the expansion device 7. Thus, it becomes a low-temperature and low-pressure two-phase refrigerant and flows into the indoor heat exchanger 8. The low-temperature and low-pressure two-phase refrigerant that has flowed into the indoor heat exchanger 8 evaporates in the indoor heat exchanger 8 to become a low-temperature and low-pressure gas refrigerant, and passes through the gas pipe 9 and the four-way valve 4 from the refrigerant gas discharge port 10a. It flows into the accumulator 10.

  The oil flowing into the accumulator 10 through the oil return pipe 14 flows into the U-shaped pipe 11 through the oil return hole 13, and flows into the accumulator 10 through the gas pipe 9 and the four-way valve 4. Flows into the inside of the U-shaped tube 11 from the opening at the tip of the U-shaped tube 11 and flows into the high-pressure shell type compressor 1 through the suction pipe 12.

  Further, since the inside of the shell of the high-pressure shell type compressor 1 is immediately after the compression mechanism of the compressor, the pressure is the highest, and the pressure due to the flow path resistance of the components of the refrigeration cycle progresses from there to the downstream side of the refrigeration cycle. The pressure gradually decreases with the decrease. Accordingly, since the pressure of the oil inflow hole 16 opened in the discharge pipe 2 is lower than the pressure of the oil outflow hole 15 opened on the shell of the high pressure shell type compressor 1, the oil in the high pressure shell type compressor 1 is reduced. Oil that tends to stay above the height of the outflow hole 15 is bypassed from the oil outflow hole 15 to the oil inflow hole 16 via the oil bypass pipe 17. Note that the diameter of the oil bypass pipe 17 is smaller than the diameter of the discharge pipe 2 to prevent excessive discharge of not only oil but also gas refrigerant from the oil bypass pipe 17.

  In this way, the liquid level of the oil staying in the lower part in the compressor does not become higher than the oil outflow hole 15, so that the liquid level of the oil does not contact the rotor, and the rotation of the rotor does not occur. Can prevent the load from being received.

Embodiment 2. FIG.
FIG. 2 is a block diagram of the refrigeration cycle in Embodiment 2 of the present invention. In the refrigeration cycle of FIG. 1, the oil outflow hole of the compressor and the oil inflow hole of the return oil pipe are connected by an oil bypass pipe. It is a thing. In FIG. 2, the same components as those in FIG. 1 and corresponding components are denoted by the same reference numerals, and description thereof is omitted.
In FIG. 2, 18 is an oil inflow hole provided in the oil return pipe 14, and 19 is an oil bypass pipe that connects the oil outflow hole 15 and the oil inflow hole 18.

  In the refrigeration cycle having this configuration, the pressure inside the shell of the high-pressure shell type compressor 1 is immediately after the compression mechanism of the compressor, so that the pressure is the highest. The pressure gradually decreases due to the pressure drop due to the channel resistance. Therefore, the pressure of the oil inflow hole 18 opened on the oil return pipe 14 is lower than the pressure of the oil outflow hole 15 opened in the shell of the high-pressure shell type compressor 1. Oil that tends to stay above the height of the outflow hole 15 is bypassed from the oil outflow hole 15 to the oil inflow hole 18 via the oil bypass pipe 19. Note that the diameter of the oil bypass pipe 19 is made smaller than the diameter of the discharge pipe 2 to prevent excessive discharge of not only oil but also gas refrigerant from the oil bypass pipe 19.

  In this way, the liquid level of the oil staying in the lower part in the compressor does not become higher than the oil outflow hole 15, so that the liquid level of the oil does not contact the rotor, and the rotation of the rotor does not occur. Can prevent the load from being received. Furthermore, since excess oil in the compressor flows directly to the oil return pipe 14 of the oil separator 3 without going through the oil separator 3, the refrigerant that flows from the discharge pipe 2 of the high-pressure shell type compressor 1 in the oil separator 3. It is only necessary to separate the oil contained therein, and the refrigerant and the oil can be sufficiently separated, so that a large amount of oil can be prevented from circulating in the refrigeration cycle, and the adverse effects associated therewith can be avoided.

Embodiment 3 FIG.
FIG. 3 is a configuration diagram of the refrigeration cycle in Embodiment 3 of the present invention. In the refrigeration cycle of FIG. 1, the oil inlet hole of the discharge pipe 2 is provided at a position lower than the oil outlet hole of the compressor. Is. In FIG. 3, the same components as those in FIG. 1 and corresponding components are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 3, reference numeral 20 denotes an oil inflow hole provided in the discharge pipe 2 so as to be positioned lower than the oil outflow hole 15 of the high-pressure shell type compressor 15. An oil bypass pipe 21 connects the oil outflow hole 15 and the oil inflow hole 20. The oil bypass pipe 21 is a straight pipe, and is therefore arranged to be inclined downward from the oil outflow hole 15 toward the oil inflow hole 20.

  In the refrigeration cycle having this configuration, the pressure inside the shell of the high-pressure shell type compressor 1 is immediately after the compression mechanism of the compressor, so that the pressure is the highest. The pressure gradually decreases due to the pressure drop due to the channel resistance. Therefore, the pressure of the oil inflow hole 20 is smaller than the pressure of the oil outflow hole 15.

  However, to bypass the oil from the oil outflow hole to the oil inflow hole when the oil inflow hole is higher than the oil outflow hole, the pressure due to the flow resistance of the components of the refrigeration cycle from the shell to the oil inflow hole Decrease, that is, the pressure difference between the pressure at the oil outflow hole and the pressure at the oil inflow hole must exceed the oil column pressure due to the rise of the oil bypass pipe from the oil outflow hole to the oil inflow hole. However, when the high-pressure shell type compressor 1 is a capacity control compressor and the refrigerant circulation amount passing through the discharge pipe can be reduced, the pressure drop due to the flow path resistance is also reduced, and the oil liquid caused by the rise of the oil bypass pipe is reduced. A phenomenon may occur in which the oil is balanced in a state where the oil pressure is below the column pressure and is raised to the middle of the oil bypass pipe, and the oil cannot be bypassed from the oil outflow hole to the oil inflow hole.

  However, in this embodiment, since the oil inflow hole 20 is disposed at a position lower than the oil outflow hole 15, the liquid column pressure of the oil due to the rise of the oil bypass pipe 21 from the oil outflow hole 15 toward the oil inflow hole 20. The oil can always be bypassed from the oil outflow hole 15 to the oil inflow hole 20.

  In this embodiment, the oil inflow hole is arranged at a position lower than the oil outflow hole. However, even when the oil is at the same height, the oil bypass pipe rises from the oil outflow hole toward the oil inflow hole. Of course, it is not necessary to consider the influence of the liquid column pressure.

  Of course, the oil return hole may be provided in the return pipe so as to be at the same position as or lower than the oil inflow hole, and the oil outflow hole and the oil inflow hole may be connected by the oil bypass pipe. Even with such a configuration, the oil can be reliably bypassed.

Embodiment 4 FIG.
FIG. 4 is a configuration diagram of a refrigeration cycle in Embodiment 4 of the present invention. In the refrigeration cycle of FIG. 1, a throttle portion is provided in the discharge pipe, and an oil inflow hole is provided downstream of the throttle portion. It is. In FIG. 4, the same components as those in FIG. 1 and corresponding components are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 4, 22 is a throttle portion provided in the discharge pipe 2, 23 is an oil inflow hole disposed downstream of the throttle portion 22 of the discharge pipe 2 as viewed from the high-pressure shell type compressor 1, and 24 is an oil outflow. An oil bypass pipe that connects the hole 15 and the oil inflow hole 23. When the oil inflow hole 15 is at a position higher than the oil outflow hole 23, the amount of restriction at the restrictor 22 is such that the pressure drop that occurs when passing through the restrictor 22 is caused by the oil outflow hole 15 of the oil bypass pipe 24. It is necessary to set so as to exceed the liquid column pressure of the oil due to the rising in the direction of the oil inflow hole 23.

  As described above, in this embodiment, the pressure in the oil outflow hole 23 can be lowered by the throttle portion 22, so that the oil inflow from the oil outflow hole 15 regardless of the height position of the oil circulation hole 15 and the oil inflow hole 23. Oil bypass to the hole 23 can be reliably performed.

Of course, a throttle part may be provided in the oil return pipe, an oil inflow hole may be provided on the downstream side of the throttle part, and the oil inflow hole and the oil outflow hole may be connected by an oil bypass pipe. Even with such a configuration, the oil can be reliably bypassed.
Further, it is naturally possible to provide the aperture portion described in the third embodiment.

Embodiment 5 FIG.
FIG. 5 is a configuration diagram of the refrigeration cycle in the fifth embodiment of the present invention. In the refrigeration cycle of FIG. 1, the oil inflow hole provided in the discharge pipe 2 and the oil provided in the high-pressure shell type compressor are shown. A pump is provided in an oil bypass pipe connecting the inflow hole. In FIG. 5, the same components as those in FIG. 1 and corresponding components are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 5, 25 is an oil inflow hole opened in the discharge pipe 2, 26 is an oil bypass pipe connecting the oil outflow hole 15 and the oil inflow hole 25, and 27 is provided in the oil bypass pipe 26. This is a pump for forcibly flowing oil from the oil inlet hole 25 to the oil inlet hole 25. In addition, when the oil inflow hole 15 is at a position higher than the oil outflow hole 25, the discharge pressure of this pump is the liquid column pressure of oil due to rising from the oil outflow hole 15 of the oil bypass pipe 24 toward the oil inflow hole 25. It is necessary to set it to exceed.

  As described above, in this embodiment, the pressure at which the oil is discharged from the oil outflow hole 255 by the pump 27 always exceeds the liquid column pressure of the oil due to the rising from the oil outflow hole 15 toward the oil inflow hole 25. Regardless of the height positions of the flow hole 15 and the oil inflow hole 25, the oil can be reliably bypassed from the oil outflow hole 15 to the oil inflow hole 25.

  Of course, an oil inflow hole may be provided in the return oil pipe, the oil inflow hole and the oil outflow hole may be connected by an oil bypass pipe, and a pump may be provided in the oil bypass pipe. Even with such a configuration, the oil can be reliably bypassed.

Embodiment 6 FIG.
FIG. 6 is a block diagram of a refrigeration cycle in Embodiment 6 of the present invention.
In FIG. 6, the refrigeration cycle connects the high pressure shell type compressor 1, the discharge pipe 2 of the high pressure shell type compressor 1, the oil separator 3, the four-way valve 4, the outdoor heat exchanger 5, and the outdoor unit and the indoor unit. Liquid pipe 6, indoor unit expansion device 7, indoor heat exchanger 8, gas pipe 9 connecting the indoor unit and the outdoor unit, accumulator 10, U-shaped pipe 11 provided in the accumulator 10, high-pressure shell type compressor 1 Mainly constructed by sequentially connecting the suction pipes 12. The expansion device 7 and the indoor heat exchanger 8 are installed in the indoor unit, and the high-pressure shell type compressor 1, the oil separator 3, the four-way valve 4, the outdoor heat exchanger 5, the accumulator 10, and the like are installed in the outdoor unit.

  The accumulator 10 is partitioned by providing a partition plate 28 in the vertical direction, and a main accumulator 29 having a function of storing liquid refrigerant and a sub-accumulator 30 having a function of storing oil in which the U-shaped tube 11 is located inside. It is divided into and. Further, the partition plate 28 is provided with a communication hole 31 on the upper side, and a gas refrigerant can be circulated between the main accumulator 29 and the sub-accumulator 30. In addition, at the lower part of the sub-accumulator 30, the other port of the oil return pipe 14 whose one port is connected to the oil separator 3 is opened.

  Further, a first oil return hole 32 that is a first oil return means is provided at the lowermost portion of the U-shaped tube 11, and a second oil return means that is a second oil return means is provided above the first oil return hole 32. An oil return hole 33 is formed.

Next, the operation during the cooling operation in the refrigeration cycle of FIG. 6 will be described.
The mixed gas of high-temperature and high-pressure gas refrigerant and oil discharged from the high-pressure shell type compressor 1 flows into the oil separator 3 through the discharge pipe 2, and is separated into gas refrigerant and oil by the oil separator 3. The separated oil flows into the sub accumulator 30 through the oil return pipe 14, and the separated gas refrigerant flows into the outdoor heat exchanger 5 through the four-way valve 4. The high-temperature and high-pressure gas refrigerant that has flowed into the outdoor heat exchanger 5 is condensed in the outdoor heat exchanger 5 and becomes a medium-temperature and high-pressure liquid refrigerant that flows into the indoor unit via the liquid pipe 6 and is throttled by the expansion device 7. It becomes a low-temperature and low-pressure two-phase refrigerant and flows into the indoor heat exchanger 8.

  The low-temperature and low-pressure two-phase refrigerant that has flowed into the indoor heat exchanger 8 evaporates in the indoor heat exchanger 8 to become a low-temperature and low-pressure gas refrigerant, and is supplied from the refrigerant gas discharge port 10 a via the gas pipe 9 and the four-way valve 4. It flows into the main accumulator 29, passes through the communication hole 31, enters the U-shaped tube 11 from the opening at the tip of the U-shaped tube 11, and flows into the high-pressure shell type compressor 1 through the suction pipe 12. The oil that has flowed into the sub-accumulator 29 via the oil return pipe 14 enters the U-shaped pipe 11 via the first oil return hole 32 or the second oil return hole 33, and is a high-pressure shell type from the suction pipe 12. It flows into the compressor 1.

Next, details of changes in the amount of oil in the sub-accumulator 30 in FIG. 6 and the amount of oil in the shell of the high-pressure shell type compressor 1 will be described with reference to FIG.
In FIG. 7, 34 indicates the level of oil remaining in the shell of the high-pressure shell type compressor 1, and 35 indicates the level of oil remaining in the sub-accumulator 30.

  In the state shown in FIG. 7 (a), since the amount of oil staying in the shell is large and the amount of oil staying in the sub-accumulator 30 is small, the liquid level 35 of the oil staying in the sub-accumulator is Although higher than the oil return hole 32, it is lower than the second oil return hole 33. Therefore, in this state, oil return to the high-pressure shell type compressor 1 is performed only from the first oil return hole 32.

  The oil discharge amount of the high-pressure shell type compressor 1 varies depending on the operation state such as the discharge pressure, the suction pressure, and the operating frequency of the high-pressure shell type compressor 1. However, if the diameter of the first oil return hole 32 is returned only from the first oil return hole 32, the amount of oil returned to the high pressure shell type compressor 1 is high regardless of the operating state. By selecting so as to be less than the oil discharge amount, the oil amount of the high-pressure shell type 1 decreases with the passage of time, and the liquid level 34 of the oil staying in the shell can be lowered.

  On the other hand, in the sub-accumulator 30, the amount of oil discharged and staying from the high-pressure shell type compressor 1 exceeds the amount of oil returning to the high-pressure shell type compressor 1. The liquid level 35 of the oil staying in can be raised with the passage of time.

  Then, after a certain period of time, from the state of FIG. 7 (a), finally, as shown in FIG. 7 (b), the liquid level 35 of the oil staying in the sub-accumulator is changed to the second level. Thus, the oil return to the high pressure shell type compressor 1 is performed from both the first oil return hole 32 and the second oil return hole 33.

  In this state, when the oil is returned from both the first oil return hole 32 and the second oil return hole 33, the diameter of the second oil return hole 33 is changed to the high-pressure shell type compressor 1 regardless of the operating state. Is selected so that the oil return amount exceeds the oil discharge amount of the high-pressure shell type compressor 1, the oil amount of the high-pressure shell type 1 is increased with the passage of time, and the oil level 34 of the oil staying in the shell is increased. On the other hand, in the sub-accumulator 30, the amount of oil discharged and staying from the high-pressure shell type compressor 1 is less than the amount of oil returning to the high-pressure shell type compressor 1, so that the oil amount is reduced. The liquid level 35 of the oil staying in the accumulator can be lowered.

  Then, as time elapses, the state changes from the state of FIG. 7B to the state of FIG. 7A, and the liquid level 35 of the oil staying in the sub-accumulator is more than the second oil return hole 33. Lower.

  Thus, in this embodiment, when the amount of oil in the high-pressure shell type compressor 1 increases from a predetermined amount, the amount of oil returned from the sub-accumulator 29 decreases, thereby reducing the amount of oil in the high-pressure shell type compressor 1. When the amount of oil decreases and, conversely, when the amount of oil in the high-pressure shell type compressor 1 decreases below a predetermined amount, the amount of oil returned from the sub-accumulator 29 increases, thereby increasing the amount of oil in the high-pressure shell type compressor 1. Since the amount of oil increases, the amount of oil staying in the shell of the high-pressure shell type compressor 1 is excessive regardless of the operating state such as the discharge pressure and suction pressure of the high-pressure shell type compressor 1 and the operating frequency. The input loss due to contact between the oil level and the rotor in the compressor can be prevented, and a large amount of oil can be contained in the refrigeration cycle. Can be prevented from circulating, it is possible to avoid the adverse effects associated therewith.

  Furthermore, oil from the return oil pipe can be concentrated in only the sub-accumulator where the U-shaped pipe is located, and it is possible to respond immediately to subtle changes in the oil amount compared to the case where the accumulator is not divided. it can. This is particularly effective in a refrigeration cycle that uses a high-pressure surrogate type compressor that has a smaller margin for oil quantity than a low-pressure shell type compressor.

In this embodiment, the amount of oil returned to the U-shaped pipe is adjusted by two holes, the first oil return hole and the second oil return hole, but is not particularly limited to this. Instead of the oil return hole, the first oil return mechanism is configured with a plurality of holes to return the same amount of oil as the first oil return hole, and the second return with the plurality of holes arranged on the top thereof. The oil mechanism may be configured to return the same amount of oil as the second oil return hole.
Furthermore, in the refrigerant cycle shown in FIGS. 1 to 6, a single high-pressure shell type compressor is used.

Embodiment 7 FIG.
The seventh embodiment of the present invention will be described below with reference to the drawings.
FIG. 8 is a refrigerant circuit diagram showing the configuration of the refrigeration apparatus of the seventh embodiment. In this figure, reference numeral 101 denotes a high-pressure shell type compressor, a compressor 111, a drive unit 112 such as a motor for driving the compressor, a main shaft 113 of the drive unit, and a lubricating oil provided at the bottom of the shell. And a storage part 114.

  Reference numeral 115 denotes a discharge part of the compressor, and 116 denotes a suction part. Further, 102 is a discharge pipe coupled to the discharge section 115, 103 is an oil drain pipe, one end is coupled to a position of height h from the bottom of the shell and opens into the shell, and the other end passes through the outside of the compressor. Connected to the discharge pipe 102.

The height h is set so that a rotor such as a motor constituting the drive unit 112 is not immersed in the lubricating oil in the storage unit 114. 114 is a four-way valve, 115 is a heat source unit side heat exchanger, 116 is a throttle device, 117 is a use side heat exchanger, 118 is an accumulator, 108a is an oil return provided at the lower part of the U-shaped outflow pipe 108b of the accumulator. A hole 109 is a suction pipe connecting the U-shaped outflow pipe 108 b of the accumulator and the suction part 116 of the compressor 101.
In addition, each apparatus mentioned above is connected by the connection piping 110 as shown in figure, and forms the refrigerant circuit which comprises a known refrigeration cycle.

  Next, the flow of the refrigerant in the refrigeration apparatus will be described. In the figure, the solid line arrows indicate the refrigerant flow in the cooling operation, and the broken line arrows indicate the refrigerant flow in the heating operation.

  First, the cooling operation will be described. The compression unit 111 is driven by the drive unit 112 in the compressor 101, and the compressed high-temperature and high-pressure gas refrigerant flows from the discharge unit 115 through the discharge pipe 102 and the four-way valve 104 to the heat source unit side heat exchanger 105, Here, heat is exchanged with the heat-source-side medium such as air or water to form a condensed liquid. The condensed and liquefied refrigerant is decompressed by the expansion device 106 to be in a gas-liquid two-phase state, and is evaporated and gasified by exchanging heat with the utilization side medium such as air in the utilization side heat exchanger 7.

  The evaporated and gasified refrigerant flows into the accumulator 108 through the four-way valve 104, and further returns from the suction unit 116 to the compressor 101 through the suction pipe 109.

  Next, the heating operation will be described. The high-temperature and high-pressure gas refrigerant compressed by the compressor 101 flows into the use side heat exchanger 7 from the discharge unit 115 through the discharge pipe 102 and the four-way valve 104, where it condenses by exchanging heat with the use side medium such as air. Liquefaction. The condensed and liquefied refrigerant is decompressed by the expansion device 106 to be in a gas-liquid two-phase state, and is evaporated and gasified by exchanging heat with the heat source side medium such as air and water in the heat source side heat exchanger 105. The evaporated and gasified refrigerant returns from the suction unit 116 to the compressor 101 via the four-way valve 104, the accumulator 108, and the suction pipe 109.

  This embodiment is configured as described above, and a pressure difference is generated between the middle portion of the discharge pipe 102 to which the oil drain pipe 103 is connected and the inside of the compressor. When the level of the height h is exceeded, the excess oil is discharged from the oil discharge pipe 103 to the discharge pipe 102 due to the pressure difference. The discharged oil returns to the accumulator 108 along the refrigerant flow described above, and the amount of oil in the accumulator 108 can be secured.

  In addition, since the distance between the main body of the compressor 101 and the discharge pipe 102 is short, the length of the oil drain pipe 103 can be shortened. Further, even when vibration occurs during operation of the compressor, the vibration compression is performed. Since the machine, the discharge pipe and the oil drain pipe vibrate almost synchronously, problems such as pipe cracks do not occur.

  The components shown in the first to sixth embodiments (FIGS. 1 to 7), the seventh embodiment (FIG. 8), and the eighth to eleventh embodiments (FIGS. 9 to 9) described later. Each component shown in FIG. 12 corresponds as follows. That is, the high-pressure shell type compressor 1 is connected to the compressor 101, the discharge pipe 2 is connected to the discharge pipe 102, the four-way valve 4 is connected to the four-way valve 104, the outdoor heat exchanger 5 is connected to the heat source side heat exchanger 105, and the liquid pipe 6 is connected. And the gas pipe 9 to the connection pipe 110, the expansion device 7 to the expansion device 106, the indoor heat exchanger 8 to the use side heat exchanger 107, the accumulator 10 to the accumulator 108, the suction pipe 12 to the suction pipe 109, The oil return hole 13 corresponds to the oil return hole 108 a, and the oil bypass pipe 17 corresponds to the oil exhaust pipe 103.

Moreover, each component of the high-pressure shell type compressor 101 shown in Embodiment 7 (FIG. 8) corresponds to each component of the high-pressure shell type compressor shown in FIG. 14 as follows. That is, the compression unit 111 is in the compression mechanism 1202, the drive unit 112 is in the rotor 1206 and the stator 1207 of the compressor motor, the main shaft 113 of the drive unit is in the rotating shaft 1205, and the lubricant stored in the storage unit 114 is in the oil 1209. The compressor discharge section 115 corresponds to the discharge pipe 1204, and the suction section 116 corresponds to the suction pipe 1201.
In addition, since correspondence of each figure of this application is understood clearly, it abbreviate | omits description one by one.

Embodiment 8 FIG.
Next, an eighth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a schematic diagram showing the configuration of the refrigeration cycle of the eighth embodiment, and shows only the compressor and the oil drain pipe. Since the other structure is the same as that of FIG. 8, illustration and description are abbreviate | omitted.

  Also, in FIG. 9, the same or corresponding parts as in FIG. The difference from FIG. 8 is that the oil drain pipe 130 is built in the compressor 101, one end (lower end in FIG. 9) opens at a height h from the bottom of the compressor 101, and the other end (upper end in FIG. 9). ) Is opened in the discharge pipe 102 in the vicinity of the discharge section through the discharge section 115 of the compressor 101. This embodiment tries to discharge oil exceeding the level of height h by using the pressure loss generated in the contracted flow portion when the high-pressure refrigerant flows into the discharge pipe 102 from the discharge portion 115 of the compressor 101. Thus, since the connection of the oil drain pipe is not necessary, the refrigerant circuit can be simplified.

Embodiment 9 FIG.
Next, a ninth embodiment of the present invention will be described with reference to the drawings.
The refrigeration cycle of this embodiment is one in which two high-pressure shell type compressors are installed and operated in parallel. FIG. 10 shows the configuration of the compressor, oil drain pipe, accumulator, and piping connection. As for the refrigerant circuit, a refrigerant circuit similar to that in FIG. 8 is formed for each compressor, but the accumulator 108 is shared as shown in the figure.

  10, the refrigerant circuit including the compressor 101 is the same as or equivalent to that in FIG. 8, and the same reference numerals as those in FIG. 8 are given to the same or corresponding parts, and the refrigerant circuit including the other compressor 101A is the same as in FIG. Alternatively, the corresponding parts are denoted by A after the reference numerals in FIG.

  In this embodiment, when the lubricating oil of the compressor 101 exceeds the height of h from the bottom which is a predetermined position, the surplus oil is discharged to the discharge pipe 102 through the oil discharge pipe 103, and is accumulated in the accumulator 108 through the refrigerant circuit. Therefore, the amount of oil in the accumulator 108 is not insufficient. Further, since the other compressor 101A is returned from the accumulator 108 through the oil return hole 108aA and the suction pipe 109A, the lubricating oil is not exhausted and the amount of oil necessary for preventing the exhaustion is reduced. be able to.

  The oil drain pipes 103 and 103A connecting the compressor and the discharge pipe do not need to be attached to all the compressors, and may be provided only for the compressor in which the amount of accumulated oil in the compressor is likely to increase. The effect can be expected. As an example in which the amount of distillate oil is likely to increase, a compressor having a small capacity when there is a difference in operating capacity among a plurality of compressors can be cited. This is because the capacity of the oil is small, so that the diffusion of oil inside the compressor is small and it is difficult for the oil to be discharged to the discharge pipe 102. Even a compressor with a variable capacity limit can be considered to be an example of requiring an oil drain pipe because it is sufficiently conceivable to have a lower capacity than the other compressor.

Embodiment 10 FIG.
Next, a tenth embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a schematic diagram showing the configuration of the refrigeration cycle of the tenth embodiment. In this figure, the same or corresponding parts as in FIG. The difference from FIG. 10 is that the oil drain pipe connecting the discharge pipe 102 and the position of the predetermined height h from the bottom surface of the compressor shell is connected to the accumulator 108 at the position of the predetermined height h from the bottom surface of the shell. This is the point that I tried to do.

In this embodiment, when the lubricating oil of the compressor 101A exceeds the height of h from the bottom which is a predetermined position, surplus oil is returned to the accumulator 108 through the oil drain pipe 103A.
For this reason, the amount of oil in the accumulator 108 does not become insufficient.

  The other compressor 101 is returned from the accumulator 108 through the oil return hole 8a and the suction pipe 109, so that the lubricating oil is not exhausted and the amount of oil necessary for preventing the exhaustion is reduced. be able to.

  The oil drain pipes 103 and 103A connecting the compressor and the discharge pipe do not need to be attached to all the compressors, and may be provided only for the compressor in which the amount of accumulated oil in the compressor is likely to increase. The effect can be expected.

In this embodiment, two compressors are installed and operated in parallel. Needless to say, the same effect as described above can be obtained even when only one compressor is used.

Embodiment 11 FIG.
Next, an eleventh embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a schematic diagram showing the configuration of the refrigeration cycle of the eleventh embodiment. In this figure, the same or corresponding parts as in FIG.

  The difference from FIG. 11 is that oil separators 120 and 120A are provided in the discharge pipes 102 and 102A of the compressor, and the connecting pipe 121 connects the oil separators 120 and 120A to the suction pipes 109 and 109A of the compressors 101 and 101A. , 121A, and the oil separated by the oil separators 120 and 120A is returned to the compressors 101 and 101A through the suction pipes 109 and 109A.

  Since this embodiment is configured as described above, the oil discharged together with the gas refrigerant from the compressors 101 and 101A is separated by the oil separators 120 and 120A, and the compressor 101 passes through the connecting pipes 121 and 121A. Therefore, regardless of the amount of oil discharged from the compressor, the oil does not stay outside the compressor, particularly in the evaporator or the condenser, and therefore the required amount of oil can be reduced.

Moreover, since the excess oil in the compressor is accumulated in the accumulator 108 through the oil drain pipes 103 and 103A, oil exhaustion of other compressors can be prevented.
In the present specification, each embodiment has been described as a refrigeration apparatus. However, this may be another name such as an air conditioner or a refrigeration cycle apparatus.

It is a block diagram of the refrigerating cycle in Embodiment 1 of this invention. It is a block diagram of the refrigerating cycle in Embodiment 2 of this invention. It is a block diagram of the refrigerating cycle in Embodiment 3 of this invention. It is a block diagram of the refrigerating cycle in Embodiment 4 of this invention. It is a block diagram of the refrigerating cycle in Embodiment 5 of this invention. It is a block diagram of the refrigerating cycle in Embodiment 6 of this invention. It is a figure which shows the liquid level of the oil of the accumulator and the compressor in Embodiment 6 of this invention. It is a refrigerant circuit diagram which shows the structure of Embodiment 7 of this invention. The structure of Embodiment 8 of this invention is shown, and it is the schematic which shows only a compressor and a waste oil pipe. The structure of Embodiment 9 of this invention is shown, and it is the schematic which shows the piping connection of a compressor, an oil drain pipe, and an accumulator. It is the schematic which shows the structure of Embodiment 10 of this invention. It is the schematic which shows the structure of Embodiment 11 of this invention. It is a block diagram of a low pressure shell type compressor. It is a block diagram of a high pressure shell type compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure shell type compressor, 2 Discharge piping, 3 Oil separator, 4 Four way valve, 5 Outdoor heat exchanger, 6 Liquid piping, 7 Throttle device, 8 Indoor heat exchanger, 9 Gas piping, 10 Accumulator, 10a Refrigerant gas Discharge port, 11 U-shaped pipe, 12 Suction pipe, 13 Oil return hole, 14 Oil return pipe, 15 Oil outflow hole, 16 Oil inflow hole, 17 Oil bypass pipe, 18 Oil inflow hole, 19 Oil bypass pipe, 20 Oil inflow hole , 21 Oil bypass pipe, 22 Restriction part, 23 Oil inflow hole, 24 Oil bypass pipe, 25 Oil inflow hole, 26 Oil bypass pipe, 27 Pump, 28 Partition plate, 29 Main accumulator, 30 Sub accumulator, 31 Communication hole, 32 First oil return hole, 33 Second oil return hole, 34 Liquid level of oil staying in shell, 35 Liquid level of oil staying in sub-accumulator, 101 Compressor, 102 discharge pipe, 103 oil drain pipe, 104 four-way valve, 105 heat source machine side heat exchanger, 107 utilization side heat exchanger, 108 accumulator, 109 suction pipe, 111 compression section, 112 drive section, 114 storage section, 115 A discharge part, 116 a suction part;

Claims (5)

A shell, a compression mechanism built in the shell, a motor including a rotation shaft, a rotor and a stator for driving the compression mechanism, and a compression mechanism built in from the lower part of the shell, and staying in the lower part of the shell A high-pressure shell type compressor having an oil distribution pipe for sending the oil to the compression mechanism, a discharge pipe connected to the high-pressure shell type compressor, and a refrigerant pipe connected to the discharge pipe to separate the refrigerant gas and the oil The refrigerant gas separated into a heat exchanger, and an oil separator that sends the oil to an accumulator via a return oil pipe,
An oil outflow hole provided at a position higher than the opening at the lower end of the oil circulation pipe of the high-pressure shell type compressor and lower than the lower end of the rotor disposed around the rotation shaft, and provided in the discharge pipe An oil inflow hole, and an oil bypass pipe that is formed with a diameter smaller than that of the discharge pipe and connects the oil outflow hole and the oil inflow hole,
A throttle part is provided on the upstream side of the oil inflow hole of the discharge pipe ,
The refrigeration apparatus according to claim 1, wherein a height position of the oil outflow hole is equal to or higher than a height position of the oil inflow hole . A high pressure shell type compressor, a discharge pipe connected to the high pressure shell type compressor, and a discharge pipe connected to the discharge pipe for separating the refrigerant gas and the oil and returning the oil to the heat exchanger. An oil separator that is sent to an accumulator via an oil pipe; a U-shaped pipe provided in the accumulator; and the refrigerant gas and oil in the accumulator connected to the U-shaped pipe and the high-pressure shell type compressor A refrigerating apparatus including a suction pipe that sends the pressure to the high-pressure shell type compressor,
A first oil return hole incorporating oil in the accumulator at the bottom of the U-shaped tube into the U-shaped tube, oil the U-shaped tube in said accumulator at a position higher than the first oil return hole a second oil return hole incorporated provided,
Further, the amount of oil sent from the first oil return hole to the U-shaped pipe is set smaller than the amount of oil discharged from the compressor to the discharge pipe regardless of the operating state of the high-pressure shell type compressor. and, the first when performing oil return by oil return holes only, a structure in which the oil amount in the accumulator the high pressure oil of the shell type compressor is reduced is increased,
The amount of oil sent to the U-shaped pipe from both the first oil return hole and the second oil return hole is discharged from the compressor to the discharge pipe regardless of the operating state of the high pressure shell type compressor. When the oil return is performed by both the first oil return hole and the second oil return hole , the oil amount of the high-pressure shell type compressor is increased. A refrigeration apparatus characterized in that the amount of oil in the accumulator is reduced. The accumulator is divided into a first chamber in which a U-shaped tube is arranged and a second chamber in which a refrigerant gas discharge port is provided by a partition plate provided in the vertical direction. The lower end of the room is provided with an open end of the oil return pipe, and the upper part of the partition plate is provided with a communication hole through which the refrigerant gas in the first room can be sent to the second room. The refrigeration apparatus according to claim 2 . The refrigeration apparatus according to any one of claims 1 to 3 , wherein a plurality of the compressors are installed and can be operated in parallel with a common accumulator of a refrigerant circuit. The apparatus for guiding surplus oil to the discharge pipe or the accumulator is provided only in a compressor in which the amount of accumulated oil in the oil storage section of each compressor is likely to increase among the plurality of compressors. 4. The refrigeration apparatus according to 4 .

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