WO2022176652A1 - Compressor for ultra-low-temperature freezer, and adsorber unit - Google Patents

Compressor for ultra-low-temperature freezer, and adsorber unit Download PDF

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Publication number
WO2022176652A1
WO2022176652A1 PCT/JP2022/004513 JP2022004513W WO2022176652A1 WO 2022176652 A1 WO2022176652 A1 WO 2022176652A1 JP 2022004513 W JP2022004513 W JP 2022004513W WO 2022176652 A1 WO2022176652 A1 WO 2022176652A1
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refrigerant gas
compressor
flow path
adsorber
main body
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PCT/JP2022/004513
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French (fr)
Japanese (ja)
Inventor
祐貴 大谷
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住友重機械工業株式会社
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Publication of WO2022176652A1 publication Critical patent/WO2022176652A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point

Definitions

  • the present invention relates to compressors and adsorber units for cryogenic refrigerators.
  • cryogenic refrigerators such as Gifford-McMahon (GM) refrigerators often use oil-lubricated compressors.
  • the high pressure refrigerant gas compressed by the compressor may contain lubricating oil, an oil separator and an adsorber are provided.
  • the oil separator separates and recovers oil from the high-pressure refrigerant gas.
  • the adsorber removes, by adsorption, residual oil components from the high-pressure refrigerant gas that has passed through the oil separator.
  • the high pressure refrigerant gas is thus cleaned by the oil separator and the adsorber and supplied to the cold head which acts as an expander.
  • Refrigerant gas whose pressure has become low due to expansion in the cold head is recovered in the compressor.
  • the compressor is provided with a bypass flow path that connects the high pressure side refrigerant gas flow path to the low pressure side refrigerant gas flow path.
  • One exemplary objective of certain aspects of the present invention is to address oil contamination that may occur in the low pressure side refrigerant gas flow path of a cryogenic refrigerator.
  • a compressor for a cryogenic refrigerator includes an oil-lubricated compressor body that compresses refrigerant gas of the cryogenic refrigerator, and is connected to the compressor body and sucked into the compressor body.
  • a discharge passage connected to the compressor body through which refrigerant gas discharged from the compressor body flows;
  • a bypass passage connecting the discharge passage to the suction passage;
  • an adsorber provided in the passage for purifying the refrigerant gas by adsorbing gaseous oil components in the refrigerant gas.
  • the bypass flow path is connected to the adsorber or downstream of the adsorber to the discharge flow path such that the refrigerant gas purified by the adsorber flows into the bypass flow path.
  • the adsorber unit includes an adsorber body that purifies the refrigerant gas of the cryogenic refrigerator by adsorbing a gaseous oil component in the refrigerant gas, and an adsorber body that is provided with the unpurified A refrigerant gas inlet into which refrigerant gas flows, and a first refrigerant gas outlet and a second refrigerant gas outlet, which are provided in the adsorber main body and through which refrigerant gas purified by the adsorber main body flows out, are provided.
  • a compressor for a cryogenic refrigerator includes an oil-lubricated compressor body that compresses refrigerant gas of the cryogenic refrigerator, and is connected to the compressor body and sucked into the compressor body. a discharge passage connected to the compressor main body through which refrigerant gas discharged from the compressor main body flows; and a bypass passage connecting the discharge passage to the suction passage. .
  • a storage tank is provided in the intake channel, and the bypass channel is connected to the storage tank or to the intake channel upstream of the storage tank.
  • a compressor for a cryogenic refrigerator further includes a refrigerant gas charge port connected to the suction flow path between the compressor body and the storage tank.
  • FIG. 1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment
  • FIG. It is a figure which shows roughly the cryogenic refrigerator which concerns on a comparative example.
  • FIG. 4 is a diagram schematically showing a cryogenic refrigerator according to another embodiment
  • FIGS. 4(a) and 4(b) are diagrams schematically showing an advertiser unit according to the embodiment.
  • FIG. 1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment.
  • the cryogenic refrigerator 10 includes a compressor 12 and a cold head 14.
  • the compressor 12 is configured to recover the refrigerant gas of the cryogenic refrigerator 10 from the cold head 14 , pressurize the recovered refrigerant gas, and supply the refrigerant gas to the cold head 14 again.
  • Compressor 12 is also referred to as a compressor unit.
  • the cold head 14, also called an expander has a room temperature section 14a and a cold section 14b, also called a cooling stage.
  • Compressor 12 and cold head 14 constitute a refrigeration cycle of cryogenic refrigerator 10, which cools low temperature section 14b to a desired cryogenic temperature.
  • the refrigerant gas also called working gas, is typically helium gas, although other suitable gases may be used.
  • Cryogenic refrigerator 10 is illustratively a single stage or two stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, Stirling refrigerator, or other type of cryogenic refrigerator. It may be a refrigerator.
  • the coldhead 14 has a different configuration depending on the type of cryogenic refrigerator 10 , but the compressor 12 can have the configuration described below regardless of the type of cryogenic refrigerator 10 .
  • the pressure of the refrigerant gas supplied from the compressor 12 to the cold head 14 and the pressure of the refrigerant gas recovered from the cold head 14 to the compressor 12 are both significantly higher than the atmospheric pressure. It can be called a second high voltage.
  • the first high pressure and the second high pressure are also simply referred to as high pressure and low pressure, respectively.
  • the high pressure is eg 2-3 MPa.
  • the low pressure is for example 0.5-1.5 MPa, for example about 0.8 MPa.
  • the compressor 12 includes a compressor body 16, an oil line 18, an oil separator 20, and an adsorber 21.
  • the compressor 12 also includes a discharge port 22, a suction port 24, a discharge passage 26, a suction passage 28, a storage tank 30, a refrigerant gas charge port 31, a bypass passage 32, a refrigerant gas cooling section 34, and an oil cooling section 36.
  • the compressor main body 16 is configured to internally compress the refrigerant gas sucked from its suction port and discharge it from its discharge port.
  • the compressor main body 16 may be, for example, a scroll type, rotary type, or other pump that pressurizes the refrigerant gas.
  • Compressor body 16 may be configured to deliver a fixed, constant refrigerant gas flow rate. Alternatively, the compressor main body 16 may be configured to vary the flow rate of the discharged refrigerant gas.
  • Compressor body 16 is sometimes referred to as a compression capsule.
  • the compressor main body 16 is an oil-lubricated type in which oil is used for lubrication and cooling, and the sucked refrigerant gas is directly exposed to this oil within the compressor main body 16 . Therefore, the refrigerant gas is sent out from the discharge port in a state in which oil is slightly mixed.
  • the oil line 18 includes an oil circulation line 18a and an oil return line 18b.
  • the oil circulation line 18a has an oil cooling portion 36, and is configured such that oil flowing out of the compressor main body 16 is cooled by the oil cooling portion 36 and flows into the compressor main body 16 again.
  • the oil circulation line 18a may be provided with an orifice for controlling the flow rate of oil flowing therein. Further, the oil circulation line 18a may be provided with a filter for removing dust contained in the oil.
  • the oil return line 18 b connects the oil separator 20 to the suction flow path 28 in order to return the oil collected by the oil separator 20 to the compressor body 16 . Refrigerant gas containing the oil recovered by the oil separator 20 flows through the oil return line 18b.
  • a filter for removing dust contained in the oil separated by the oil separator 20 and an orifice for controlling the amount of oil returned to the compressor body 16 may be provided in the middle of the oil return line 18b.
  • the oil separator 20 is provided to separate the oil mixed in the refrigerant gas from the refrigerant gas as it passes through the compressor body 16 .
  • the oil separator 20 is connected to the discharge port of the compressor main body 16 through the upstream portion 26a of the discharge passage 26. As shown in FIG. Further, the oil separator 20 is connected to the discharge port 22 through the downstream portion 26b of the discharge flow path 26. As shown in FIG.
  • the adsorber 21 is provided in the discharge flow path 26 and purifies the refrigerant gas by adsorbing gaseous oil components (for example, vaporized oil or oil mist) and moisture in the refrigerant gas.
  • the adsorber 21 is arranged on the discharge passage 26 in the middle of the downstream portion 26 b of the discharge passage 26 , that is, between the oil separator 20 and the discharge port 22 .
  • the adsorber 21 may be configured as an adsorber unit that can be attached to and detached from the compressor 12 .
  • the discharge port 22 is a refrigerant gas outlet installed in the compressor housing 38 for sending out the refrigerant gas pressurized to a high pressure by the compressor body 16 from the compressor 12, and the suction port 24 is a low pressure refrigerant gas outlet.
  • a refrigerant gas inlet located in the compressor housing 38 for receiving the gas into the compressor 12 .
  • a discharge passage 26 connects the discharge port 22 to the discharge port of the compressor body 16 . Refrigerant gas discharged from the compressor main body 16 to the discharge port 22 flows through the discharge flow path 26 .
  • a suction passage 28 connects the suction port 24 to the suction port of the compressor body 16 . Refrigerant gas sucked into the compressor main body 16 from the suction port 24 flows through the suction passage 28 .
  • Each of the discharge channel 26 and the suction channel 28 is internal piping of the compressor 12 provided within the compressor housing 38, and may be a flexible tube or a rigid tube.
  • the storage tank 30 is provided as a volume for removing pulsation contained in the low pressure refrigerant gas returning from the cold head 14 to the compressor 12 .
  • the storage tank 30 is arranged in the suction flow path 28 .
  • the refrigerant gas charge port 31 is provided in the compressor housing 38 as a filling port for filling the cryogenic refrigerator 10 with refrigerant gas.
  • Refrigerant gas charge port 31 is connected to suction channel 28 between storage tank 30 and suction port 24 in this embodiment.
  • refrigerant gas charge port 31 may be connected to storage tank 30 .
  • the refrigerant gas charge port 31 may normally be closed with a lid. When the refrigerant gas is charged, the refrigerant gas charge port 31 is connected to the refrigerant gas tank, and the refrigerant gas is supplied from there through the refrigerant gas charge port 31 into the compressor 12 .
  • the bypass flow path 32 is connected to the Adsorber 21 or to the discharge flow path 26 downstream of the Adsorber 21 so that the refrigerant gas purified by the Adsorber 21 flows into the bypass flow path.
  • the bypass channel 32 is connected to the discharge channel 26 between the adsorber 21 and the discharge port 22 .
  • a bypass flow path 32 is also connected to the storage tank 30 , thereby connecting the discharge flow path 26 to the suction flow path 28 .
  • the bypass flow path 32 is provided to equalize the pressure on the high pressure side and the low pressure side when the cryogenic refrigerator 10 is stopped.
  • a bypass valve 33 is provided in the bypass flow path 32 .
  • Bypass valve 33 is closed during operation of compressor 12 (that is, when compressor 12 is on) to block refrigerant gas flow through bypass flow path 32 .
  • Bypass valve 33 is opened when stopping compressor 12 (when switching compressor 12 from on to off). By opening the bypass valve 33, the refrigerant gas is allowed to flow from the discharge passage 26 to the suction passage 28 through the bypass passage 32, and the refrigerant gas pressures in the discharge passage 26 and the suction passage 28 are equalized.
  • the bypass valve 33 may be a normally open on-off valve, and may be naturally opened when power supply to the compressor 12 is stopped.
  • a flow control valve may be provided in parallel with the bypass valve 33 in the bypass flow path 32 .
  • the differential pressure between the discharge channel 26 and the suction channel 28 may be adjusted using this flow control valve.
  • the refrigerant gas cooling unit 34 and the oil cooling unit 36 constitute a cooling system that cools the compressor 12 using a cooling medium such as cooling water.
  • the refrigerant gas cooling part 34 is arranged in the upstream part 26 a of the discharge passage 26 and is provided to cool the high-pressure refrigerant gas heated by the heat of compression generated as the refrigerant gas is compressed in the compressor main body 16 . ing.
  • the refrigerant gas cooling unit 34 cools the refrigerant gas by heat exchange between the refrigerant gas and the cooling medium.
  • the oil cooling portion 36 cools the oil by heat exchange between the oil flowing out from the compressor main body 16 and the cooling medium.
  • a cooling medium is supplied to the compressor 12 from the outside, passes through the refrigerant gas cooling section 34 and the oil cooling section 36, and is discharged to the outside of the compressor 12. As shown in FIG. In this way, the heat of compression generated in the compressor body 16 is removed out of the compressor 12 along with the cooling medium.
  • the cooling medium may be cooled by, for example, a chiller (not shown) and supplied again.
  • Compressor housing 38 accommodates each component of compressor 12 such as compressor main body 16, oil separator 20 on discharge passage 26, adsorber 21, and storage tank 30 on intake passage 28. there is A refrigerant gas cooling portion 34 and an oil cooling portion 36 are also housed in the compressor housing 38 .
  • the cryogenic refrigerator 10 also includes a high pressure port 40 and a low pressure port 41 in the room temperature section 14 a of the cold head 14 .
  • the high pressure port 40 is connected to the discharge port 22 by a high pressure pipe 42 and the low pressure port 41 is connected to the suction port 24 by a low pressure pipe 43 .
  • the high pressure piping 42 and the low pressure piping 43 are arranged outside the compressor 12 .
  • the high pressure pipe 42 and the low pressure pipe 43 are flexible pipes, but they may also be rigid pipes.
  • the cryogenic refrigerator 10 may include a main switch 50 for switching the cryogenic refrigerator 10 on and off.
  • the main switch 50 may be installed on the compressor 12 . When the main switch 50 is on, the compressor 12 and the cold head 14 are operated, and when the main switch 50 is off, the compressor 12 and the cold head 14 are stopped.
  • the main switch 50 may be manually operable. Additionally or alternatively, the main switch 50 may be automatically switched according to predetermined conditions. For example, main switch 50 may turn cryocooler 10 on or off according to a predetermined schedule.
  • the compressor body 16 may deliver a fixed, constant refrigerant gas flow rate, which forces the motor driving the compressor body 16 to operate at a constant speed (i.e., a constant operating frequency). in).
  • on/off switching of the cryogenic refrigerator 10 by the main switch 50 may be used for energy saving.
  • the object to be cooled by the cryogenic refrigerator 10 is a sensor that is used in a cryogenic environment (for example, the measurement accuracy is improved by being used in a state of being cooled to a cryogenic temperature)
  • the cryocooler 10 may be switched off during measurements by this sensor in order to suppress vibrations generated by the operation of the cryocooler 10 and further improve measurement accuracy.
  • the refrigerant gas recovered from the cold head 14 into the compressor 12 is supplied from the low pressure port 41 to the suction port 24 of the compressor 12 through the low pressure pipe 43. influx.
  • the refrigerant gas passes through the storage tank 30 on the suction flow path 28 and is recovered to the suction port of the compressor main body 16 .
  • the refrigerant gas is compressed and pressurized by the compressor main body 16 .
  • Refrigerant gas delivered from the discharge port of the compressor main body 16 is cooled by the refrigerant gas cooling portion 34 on the discharge passage 26 and then purified by the oil separator 20 and the adsorber 21 .
  • Most of the oil mixed in the refrigerant gas in the compressor main body 16 is separated by the oil separator 20 and recovered to the compressor main body 16 .
  • the refrigerant gas that has passed through the oil separator 20 is supplied to the adsorber 21, and the gaseous oil component remaining in the refrigerant gas is adsorbed by the adsorber 21 and removed. Since the bypass valve 33 is closed at this time, the clean high-pressure refrigerant gas coming out of the adsorber 21 goes to the discharge port 22 instead of the bypass flow path 32 .
  • Refrigerant gas exits the compressor 12 through the discharge port 22 and is supplied to the interior of the cold head 14 via the high pressure pipe 42 and the high pressure port 40 . Due to the adiabatic expansion of the refrigerant gas inside the cold head 14, the low temperature portion 14b of the cold head 14 is cooled. The low-pressure refrigerant gas is recovered from the cold head 14 to the compressor 12 again.
  • the bypass valve 33 is opened as described above. Since the bypass flow path 32 is connected to the discharge flow path 26 downstream of the adsorber 21 , the high-pressure gas purified by the adsorber 21 flows from the discharge flow path 26 into the suction flow path 28 through the bypass flow path 32 . In this way, the refrigerant gas pressures on the high pressure side and the low pressure side of the cryogenic refrigerator 10 are equalized.
  • FIG. 2 is a diagram schematically showing a cryogenic refrigerator 100 according to a comparative example.
  • This cryogenic refrigerator 100 differs from the above-described embodiment with respect to the connection of the bypass flow path 132, and the remainder is the same.
  • the bypass flow path 132 branches from the discharge flow path 26 between the oil separator 20 and the adsorber 21 to the storage tank 30. Connected.
  • the low-pressure side refrigerant gas passage (for example, the suction passage 28, the low-pressure pipe 43, We have discovered that the refrigerant gas charge port 31) is sometimes contaminated with oil.
  • This backflowing refrigerant gas is oil-separated by the oil separator 20, but since it does not pass through the adsorber 21, it may contain a gaseous oil component (albeit in a very small amount). Therefore, oil gradually accumulates in the low-pressure side refrigerant gas flow path by receiving a very large number of refrigerant gas backflows (for example, about 2500 on-off switching and accompanying pressure equalization and refrigerant gas backflow) during long-term operation. It is considered that the contamination has progressed. In the case of contamination, troublesome maintenance work such as cleaning of the inside of the flow path and replacement of piping is required, which is time-consuming and costly.
  • oil may accumulate in the refrigerant gas charge port 31 due to backflow to the refrigerant gas charge port 31 .
  • the oil may spout out together with the gas and contaminate the surroundings.
  • a compressor equipped with an inverter is used in a cryogenic refrigerator for energy saving.
  • it is extremely rare to experience frequent on/off switching. Therefore, in the inverter-mounted compressor, it can be considered that oil contamination on the low-pressure side does not actually occur even with the bypass flow path connection of the comparative example. Therefore, the problem of oil contamination in the low-pressure side refrigerant gas flow path described above can be said to be unique to the above-described configuration that aims to improve energy saving by switching the cryogenic refrigerator 10 on and off instead of installing an inverter.
  • the refrigerant gas purified by the adsorber 21 flows from the discharge flow path 26 to the suction flow path 28 through the bypass flow path 32. . Even if the refrigerant gas flows back into the refrigerant gas passage on the low pressure side, the refrigerant gas is purified by the adsorber 21, so oil contamination in the refrigerant gas passage on the low pressure side is avoided as much as possible. Therefore, the above-mentioned problems such as troublesome maintenance work caused by oil contamination and oil spouting from the refrigerant gas charge port 31 can be eliminated or reduced.
  • FIG. 3 is a diagram schematically showing a cryogenic refrigerator according to another embodiment.
  • This cryogenic refrigerator 10 differs from the embodiment shown in FIG. 1 with respect to the refrigerant gas charge port 31 and the bypass passage 132, and the rest is the same.
  • the refrigerant gas charge port 31 is connected to the suction flow path 28 between the compressor body 16 and the storage tank 30 .
  • the bypass flow path 132 branches from the discharge flow path 26 between the oil separator 20 and the adsorber 21 and is connected to the storage tank 30, as in the comparative example shown in FIG. Note that the bypass flow path 132 may be connected to the intake flow path 28 upstream of the storage tank 30 (that is, between the intake port 24 and the storage tank 30).
  • backflow of the refrigerant gas to the suction flow path 28 through the bypass flow path 132 may occur during pressure equalization.
  • reverse flow of the refrigerant gas to the refrigerant gas charge port 31 is less likely to occur. This is because the volume of the flow path to the refrigerant gas charge port 31 is smaller than the volume of the low pressure side flow path from the suction flow path 28 to the low pressure port 41 through the low pressure pipe 43 .
  • bypass channel 32 shown in FIG. 1 may be used instead of the bypass channel 132. That is, the bypass channel 32 may be connected to the adsorber 21 or downstream of the adsorber 21 to the discharge channel 26 so that the refrigerant gas purified by the adsorber 21 flows into the bypass channel.
  • FIGS. 4(a) and 4(b) are diagrams schematically showing an advertiser unit according to the embodiment.
  • the adsorber unit shown in FIGS. 4(a) and 4(b) can be used as the adsorber 21 in the embodiment shown in FIGS. 1 and 3, and can be attached/detached to/from the compressor.
  • the adsorber unit includes an adsorber main body 21a, a refrigerant gas inlet 21b into which unpurified refrigerant gas 52 flows, and a refrigerant gas purified by the adsorber 21.
  • 54 is provided with a first refrigerant gas outlet 21c and a second refrigerant gas outlet 21d.
  • the adsorber main body 21a is a cylindrical container containing an adsorbent such as activated carbon.
  • the adsorber main body 21a purifies the refrigerant gas of the cryogenic refrigerator 10 by adsorbing gaseous oil components in the refrigerant gas.
  • the refrigerant gas inlet 21b is provided at one end (for example, the lower end) of the adsorber main body 21a, and the first refrigerant gas outlet 21c and the first refrigerant gas outlet 21c are provided at the other end (for example, the upper end) of the adsorber main body 21a.
  • the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d are provided in branch pipes provided in the adsorber main body 21a.
  • the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d are separately provided in the adsorber main body 21a.
  • the refrigerant gas inlet 21b is connected to the oil separator 20 shown in FIGS. 1 to 3.
  • a bypass flow path 32 is connected to either the first refrigerant gas outlet 21c or the second refrigerant gas outlet 21d, and the discharge port 22 is connected to the other of them.
  • the refrigerant gas inlet 21b, the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d may be detachable couplings such as self-sealing couplings.
  • bypass flow path 32 is provided inside the compressor 12 in the above embodiment, it may be provided outside the compressor 12 .
  • the bypass flow path 32 may be located outside the compressor housing 38 and connect the high pressure line 42 and the low pressure line 43 . Even in this way, the high-pressure refrigerant gas purified by the adsorber 21 can be returned to the low-pressure side during pressure equalization. It is possible to prevent contamination. It is possible to avoid oil contamination of the refrigerant gas passage on the low pressure side.
  • the high pressure line 42 may be considered to be part of the discharge channel 26 and the low pressure line 43 to be part of the suction channel 28 .
  • the cryogenic refrigerator 10 may be switched off during measurement by this sensor. Therefore, when the on/off switching of the cryogenic refrigerator 10 is performed in accordance with such sensor measurement, it cannot be denied that oil contamination on the low-pressure side may occur even with an inverter-mounted compressor. Therefore, the adsorber 21 according to the embodiment or the bypass flow path 32 connected to the discharge flow path downstream of the adsorber 21 may be applied to an inverter-mounted compressor.
  • the present invention can be used in the field of compressors and adsorber units for cryogenic refrigerators.

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Abstract

This compressor (12) for an ultra-low-temperature freezer comprises: an oil-lubricated compressor body (16) that compresses a refrigerant gas in an ultra-low-temperature freezer (10); an intake flow path (28), which is connected to the compressor body (16) and through which flows the refrigerant gas taken into the compressor body (16); a discharge flow path (26), which is connected to the compressor body (16) and through which flows the refrigerant gas discharged from the compressor body (16); a bypass flow path (32) that connects the discharge flow path (26) to the intake flow path (28); and an adsorber (21) that is provided to the discharge flow path (26) and that purifies the refrigerant gas through adsorption of a gaseous oil component in the refrigerant gas. The bypass flow path (32) is connected to the adsorber (21), or to the discharge flow path (26) at a location further downstream than the adsorber (21), such that the refrigerant gas purified by the adsorber (21) flows into the bypass flow path (32).

Description

極低温冷凍機用の圧縮機およびアドゾーバユニットCompressor and Adsorber Units for Cryogenic Refrigerators
　本発明は、極低温冷凍機用の圧縮機およびアドゾーバユニットに関する。 The present invention relates to compressors and adsorber units for cryogenic refrigerators.
　一般に、ギフォード・マクマホン（Gifford-McMahon；ＧＭ）冷凍機などの極低温冷凍機では、オイル潤滑式の圧縮機がよく用いられている。圧縮機で圧縮された高圧の冷媒ガスは潤滑オイルを含有しうるので、オイルセパレータとアドゾーバが設けられている。オイルセパレータは、高圧冷媒ガスからオイルを分離・回収する。アドゾーバは、オイルセパレータを通過した高圧冷媒ガスから残留オイル成分を吸着により除去する。高圧冷媒ガスは、こうしてオイルセパレータとアドゾーバにより清浄化され、膨張機として働くコールドヘッドに供給される。コールドヘッドでの膨張により低圧となった冷媒ガスは、圧縮機に回収される。圧縮機には、高圧側の冷媒ガス流路を低圧側の冷媒ガス流路につなぐバイパス流路が設けられている。 In general, cryogenic refrigerators such as Gifford-McMahon (GM) refrigerators often use oil-lubricated compressors. Since the high pressure refrigerant gas compressed by the compressor may contain lubricating oil, an oil separator and an adsorber are provided. The oil separator separates and recovers oil from the high-pressure refrigerant gas. The adsorber removes, by adsorption, residual oil components from the high-pressure refrigerant gas that has passed through the oil separator. The high pressure refrigerant gas is thus cleaned by the oil separator and the adsorber and supplied to the cold head which acts as an expander. Refrigerant gas whose pressure has become low due to expansion in the cold head is recovered in the compressor. The compressor is provided with a bypass flow path that connects the high pressure side refrigerant gas flow path to the low pressure side refrigerant gas flow path.
特開２００１－７４３２６号公報JP 2001-74326 A
　本発明者は、上記の極低温冷凍機ではオイル除去された冷媒ガスがコールドヘッドに供給されているにもかかわらず、コールドヘッドから圧縮機に回収される低圧冷媒ガスが流れる低圧側の冷媒ガス流路が時にオイルで汚染されることを発見した。 In the above-described cryogenic refrigerator, although the oil-removed refrigerant gas is supplied to the cold head, the low-pressure refrigerant gas collected from the cold head to the compressor flows. We have found that the flow path is sometimes contaminated with oil.
　本発明のある態様の例示的な目的のひとつは、極低温冷凍機の低圧側冷媒ガス流路に生じうるオイル汚染に対処することにある。 One exemplary objective of certain aspects of the present invention is to address oil contamination that may occur in the low pressure side refrigerant gas flow path of a cryogenic refrigerator.
　本発明のある態様によると、極低温冷凍機用の圧縮機は、極低温冷凍機の冷媒ガスを圧縮するオイル潤滑式の圧縮機本体と、圧縮機本体に接続され、圧縮機本体に吸入される冷媒ガスが流れる吸入流路と、圧縮機本体に接続され、圧縮機本体から吐出される冷媒ガスが流れる吐出流路と、吐出流路を吸入流路に接続するバイパス流路と、吐出流路に設けられ、冷媒ガス中のガス状オイル成分を吸着することにより冷媒ガスを浄化するアドゾーバと、を備える。バイパス流路は、アドゾーバで浄化された冷媒ガスがバイパス流路に流入するように、アドゾーバに、またはアドゾーバよりも下流で吐出流路に接続されている。 According to one aspect of the present invention, a compressor for a cryogenic refrigerator includes an oil-lubricated compressor body that compresses refrigerant gas of the cryogenic refrigerator, and is connected to the compressor body and sucked into the compressor body. a discharge passage connected to the compressor body through which refrigerant gas discharged from the compressor body flows; a bypass passage connecting the discharge passage to the suction passage; an adsorber provided in the passage for purifying the refrigerant gas by adsorbing gaseous oil components in the refrigerant gas. The bypass flow path is connected to the adsorber or downstream of the adsorber to the discharge flow path such that the refrigerant gas purified by the adsorber flows into the bypass flow path.
　本発明のある態様によると、アドゾーバユニットは、極低温冷凍機の冷媒ガスを、冷媒ガス中のガス状オイル成分を吸着することにより浄化するアドゾーバ本体と、アドゾーバ本体に設けられ、未浄化の冷媒ガスが流入する冷媒ガス入口と、アドゾーバ本体に設けられ、アドゾーバ本体で浄化された冷媒ガスが流出する第１冷媒ガス出口および第２冷媒ガス出口と、を備える。 According to one aspect of the present invention, the adsorber unit includes an adsorber body that purifies the refrigerant gas of the cryogenic refrigerator by adsorbing a gaseous oil component in the refrigerant gas, and an adsorber body that is provided with the unpurified A refrigerant gas inlet into which refrigerant gas flows, and a first refrigerant gas outlet and a second refrigerant gas outlet, which are provided in the adsorber main body and through which refrigerant gas purified by the adsorber main body flows out, are provided.
　本発明のある態様によると、極低温冷凍機用の圧縮機は、極低温冷凍機の冷媒ガスを圧縮するオイル潤滑式の圧縮機本体と、圧縮機本体に接続され、圧縮機本体に吸入される冷媒ガスが流れる吸入流路と、圧縮機本体に接続され、圧縮機本体から吐出される冷媒ガスが流れる吐出流路と、吐出流路を吸入流路に接続するバイパス流路と、を備える。吸入流路には、ストレージタンクが設けられ、バイパス流路は、ストレージタンクに、またはストレージタンクよりも上流で吸入流路に接続されている。極低温冷凍機用の圧縮機は、圧縮機本体とストレージタンクとの間で吸入流路に接続された冷媒ガスチャージポートをさらに備える。 According to one aspect of the present invention, a compressor for a cryogenic refrigerator includes an oil-lubricated compressor body that compresses refrigerant gas of the cryogenic refrigerator, and is connected to the compressor body and sucked into the compressor body. a discharge passage connected to the compressor main body through which refrigerant gas discharged from the compressor main body flows; and a bypass passage connecting the discharge passage to the suction passage. . A storage tank is provided in the intake channel, and the bypass channel is connected to the storage tank or to the intake channel upstream of the storage tank. A compressor for a cryogenic refrigerator further includes a refrigerant gas charge port connected to the suction flow path between the compressor body and the storage tank.
　本発明によれば、極低温冷凍機の低圧側冷媒ガス流路に生じうるオイル汚染に対処することができる。 According to the present invention, it is possible to deal with oil contamination that may occur in the low-pressure side refrigerant gas flow path of the cryogenic refrigerator.
実施の形態に係る極低温冷凍機を概略的に示す図である。1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment; FIG. 比較例に係る極低温冷凍機を概略的に示す図である。It is a figure which shows roughly the cryogenic refrigerator which concerns on a comparative example. 他の実施の形態に係る極低温冷凍機を概略的に示す図である。FIG. 4 is a diagram schematically showing a cryogenic refrigerator according to another embodiment; 図４（ａ）および図４（ｂ）は、実施の形態に係るアドゾーバユニットを概略的に示す図である。FIGS. 4(a) and 4(b) are diagrams schematically showing an advertiser unit according to the embodiment. FIG.
　以下、図面を参照しながら、本発明を実施するための形態について詳細に説明する。説明および図面において同一または同等の構成要素、部材、処理には同一の符号を付し、重複する説明は適宜省略する。図示される各部の縮尺や形状は、説明を容易にするために便宜的に設定されており、特に言及がない限り限定的に解釈されるものではない。実施の形態は例示であり、本発明の範囲を何ら限定するものではない。実施の形態に記述されるすべての特徴やその組み合わせは、必ずしも発明の本質的なものであるとは限らない。 Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience in order to facilitate explanation, and should not be construed as limiting unless otherwise specified. The embodiment is an example and does not limit the scope of the present invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.
　図１は、実施の形態に係る極低温冷凍機を概略的に示す図である。 FIG. 1 is a diagram schematically showing a cryogenic refrigerator according to an embodiment.
　極低温冷凍機１０は、圧縮機１２と、コールドヘッド１４とを備える。圧縮機１２は、極低温冷凍機１０の冷媒ガスをコールドヘッド１４から回収し、回収した冷媒ガスを昇圧して、再び冷媒ガスをコールドヘッド１４に供給するよう構成されている。圧縮機１２は、圧縮機ユニットとも称される。コールドヘッド１４は、膨張機とも称され、室温部１４ａと、冷却ステージとも称される低温部１４ｂとを有する。圧縮機１２とコールドヘッド１４により極低温冷凍機１０の冷凍サイクルが構成され、それにより低温部１４ｂが所望の極低温に冷却される。冷媒ガスは、作動ガスとも称され、通例はヘリウムガスであるが、適切な他のガスが用いられてもよい。 The cryogenic refrigerator 10 includes a compressor 12 and a cold head 14. The compressor 12 is configured to recover the refrigerant gas of the cryogenic refrigerator 10 from the cold head 14 , pressurize the recovered refrigerant gas, and supply the refrigerant gas to the cold head 14 again. Compressor 12 is also referred to as a compressor unit. The cold head 14, also called an expander, has a room temperature section 14a and a cold section 14b, also called a cooling stage. Compressor 12 and cold head 14 constitute a refrigeration cycle of cryogenic refrigerator 10, which cools low temperature section 14b to a desired cryogenic temperature. The refrigerant gas, also called working gas, is typically helium gas, although other suitable gases may be used.
　極低温冷凍機１０は、一例として、単段式または二段式のギフォード・マクマホン（Gifford-McMahon；ＧＭ）冷凍機であるが、パルス管冷凍機、スターリング冷凍機、またはそのほかのタイプの極低温冷凍機であってもよい。コールドヘッド１４は、極低温冷凍機１０のタイプに応じて異なる構成を有するが、圧縮機１２は、極低温冷凍機１０のタイプによらず、以下に説明する構成を用いることができる。 Cryogenic refrigerator 10 is illustratively a single stage or two stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, Stirling refrigerator, or other type of cryogenic refrigerator. It may be a refrigerator. The coldhead 14 has a different configuration depending on the type of cryogenic refrigerator 10 , but the compressor 12 can have the configuration described below regardless of the type of cryogenic refrigerator 10 .
　なお、一般に、圧縮機１２からコールドヘッド１４に供給される冷媒ガスの圧力と、コールドヘッド１４から圧縮機１２に回収される冷媒ガスの圧力は、ともに大気圧よりかなり高く、それぞれ第１高圧及び第２高圧と呼ぶことができる。説明の便宜上、第１高圧及び第２高圧はそれぞれ単に高圧及び低圧とも呼ばれる。典型的には、高圧は例えば２～３ＭＰａである。低圧は例えば０．５～１．５ＭＰａであり、例えば約０．８ＭＰａである。 In general, the pressure of the refrigerant gas supplied from the compressor 12 to the cold head 14 and the pressure of the refrigerant gas recovered from the cold head 14 to the compressor 12 are both significantly higher than the atmospheric pressure. It can be called a second high voltage. For convenience of explanation, the first high pressure and the second high pressure are also simply referred to as high pressure and low pressure, respectively. Typically the high pressure is eg 2-3 MPa. The low pressure is for example 0.5-1.5 MPa, for example about 0.8 MPa.
　圧縮機１２は、圧縮機本体１６、オイルライン１８、オイルセパレータ２０、アドゾーバ２１を備える。また、圧縮機１２は、吐出ポート２２、吸入ポート２４、吐出流路２６、吸入流路２８、ストレージタンク３０、冷媒ガスチャージポート３１、バイパス流路３２、冷媒ガス冷却部３４、オイル冷却部３６を備える。 The compressor 12 includes a compressor body 16, an oil line 18, an oil separator 20, and an adsorber 21. The compressor 12 also includes a discharge port 22, a suction port 24, a discharge passage 26, a suction passage 28, a storage tank 30, a refrigerant gas charge port 31, a bypass passage 32, a refrigerant gas cooling section 34, and an oil cooling section 36. Prepare.
　圧縮機本体１６は、その吸入口から吸入される冷媒ガスを内部で圧縮して吐出口から吐出するよう構成されている。圧縮機本体１６は、例えば、スクロール方式、ロータリ式、または冷媒ガスを昇圧するそのほかのポンプであってもよい。圧縮機本体１６は、固定された一定の冷媒ガス流量を吐出するよう構成されていてもよい。あるいは、圧縮機本体１６は、吐出する冷媒ガス流量を可変とするよう構成されていてもよい。圧縮機本体１６は、圧縮カプセルと称されることもある。 The compressor main body 16 is configured to internally compress the refrigerant gas sucked from its suction port and discharge it from its discharge port. The compressor main body 16 may be, for example, a scroll type, rotary type, or other pump that pressurizes the refrigerant gas. Compressor body 16 may be configured to deliver a fixed, constant refrigerant gas flow rate. Alternatively, the compressor main body 16 may be configured to vary the flow rate of the discharged refrigerant gas. Compressor body 16 is sometimes referred to as a compression capsule.
　圧縮機本体１６は、潤滑と冷却のためにオイルが使用されるオイル潤滑式であり、吸入された冷媒ガスは圧縮機本体１６内でこのオイルに直接さらされる。よって、冷媒ガスは、オイルが若干混入した状態で吐出口から送出される。 The compressor main body 16 is an oil-lubricated type in which oil is used for lubrication and cooling, and the sucked refrigerant gas is directly exposed to this oil within the compressor main body 16 . Therefore, the refrigerant gas is sent out from the discharge port in a state in which oil is slightly mixed.
　オイルライン１８は、オイル循環ライン１８ａと、オイル戻りライン１８ｂとを備える。オイル循環ライン１８ａは、オイル冷却部３６を有し、圧縮機本体１６から流出するオイルがオイル冷却部３６により冷却され再び圧縮機本体１６に流入するように構成されている。オイル循環ライン１８ａには、内部を流れるオイル流量を制御するオリフィスが設けられていてもよい。また、オイル循環ライン１８ａには、オイルに含まれる塵埃を除去するフィルターが設けられてもよい。オイル戻りライン１８ｂは、オイルセパレータ２０で回収されたオイルを圧縮機本体１６に戻すために、オイルセパレータ２０を吸入流路２８に接続する。オイル戻りライン１８ｂには、オイルセパレータ２０で回収されたオイルを含む冷媒ガスが流れる。オイル戻りライン１８ｂの途中には、オイルセパレータ２０で分離されたオイルに含まれる塵埃を除去するフィルターと、圧縮機本体１６へのオイルの戻り量を制御するオリフィスが設けられてもよい。 The oil line 18 includes an oil circulation line 18a and an oil return line 18b. The oil circulation line 18a has an oil cooling portion 36, and is configured such that oil flowing out of the compressor main body 16 is cooled by the oil cooling portion 36 and flows into the compressor main body 16 again. The oil circulation line 18a may be provided with an orifice for controlling the flow rate of oil flowing therein. Further, the oil circulation line 18a may be provided with a filter for removing dust contained in the oil. The oil return line 18 b connects the oil separator 20 to the suction flow path 28 in order to return the oil collected by the oil separator 20 to the compressor body 16 . Refrigerant gas containing the oil recovered by the oil separator 20 flows through the oil return line 18b. A filter for removing dust contained in the oil separated by the oil separator 20 and an orifice for controlling the amount of oil returned to the compressor body 16 may be provided in the middle of the oil return line 18b.
　オイルセパレータ２０は、圧縮機本体１６を通ることによって冷媒ガスに混入するオイルを冷媒ガスから分離するために設けられている。オイルセパレータ２０は、吐出流路２６の上流部２６ａを通じて圧縮機本体１６の吐出口に接続されている。また、オイルセパレータ２０は、吐出流路２６の下流部２６ｂを通じて吐出ポート２２に接続されている。 The oil separator 20 is provided to separate the oil mixed in the refrigerant gas from the refrigerant gas as it passes through the compressor body 16 . The oil separator 20 is connected to the discharge port of the compressor main body 16 through the upstream portion 26a of the discharge passage 26. As shown in FIG. Further, the oil separator 20 is connected to the discharge port 22 through the downstream portion 26b of the discharge flow path 26. As shown in FIG.
　アドゾーバ２１は、吐出流路２６に設けられ、冷媒ガス中のガス状オイル成分（例えば、気化したオイルやミスト状のオイルなど）や水分を吸着することにより冷媒ガスを浄化する。アドゾーバ２１は、吐出流路２６の下流部２６ｂの途中、つまりオイルセパレータ２０と吐出ポート２２の間で吐出流路２６上に配置されている。後述のように、アドゾーバ２１は、圧縮機１２に着脱可能なアドゾーバユニットとして構成されてもよい。 The adsorber 21 is provided in the discharge flow path 26 and purifies the refrigerant gas by adsorbing gaseous oil components (for example, vaporized oil or oil mist) and moisture in the refrigerant gas. The adsorber 21 is arranged on the discharge passage 26 in the middle of the downstream portion 26 b of the discharge passage 26 , that is, between the oil separator 20 and the discharge port 22 . As will be described later, the adsorber 21 may be configured as an adsorber unit that can be attached to and detached from the compressor 12 .
　吐出ポート２２は、圧縮機本体１６により高圧に昇圧された冷媒ガスを圧縮機１２から送出するために圧縮機筐体３８に設置された冷媒ガスの出口であり、吸入ポート２４は、低圧の冷媒ガスを圧縮機１２に受け入れるために圧縮機筐体３８に設置された冷媒ガスの入口である。吐出流路２６は、吐出ポート２２を圧縮機本体１６の吐出口に接続する。吐出流路２６には、圧縮機本体１６から吐出ポート２２へと吐出される冷媒ガスが流れる。吸入流路２８は、吸入ポート２４を圧縮機本体１６の吸入口に接続する。吸入流路２８には、吸入ポート２４から圧縮機本体１６に吸入される冷媒ガスが流れる。吐出流路２６と吸入流路２８はそれぞれ、圧縮機筐体３８内に設けられた圧縮機１２の内部配管であり、フレキシブル管またはリジッド管であってもよい。 The discharge port 22 is a refrigerant gas outlet installed in the compressor housing 38 for sending out the refrigerant gas pressurized to a high pressure by the compressor body 16 from the compressor 12, and the suction port 24 is a low pressure refrigerant gas outlet. A refrigerant gas inlet located in the compressor housing 38 for receiving the gas into the compressor 12 . A discharge passage 26 connects the discharge port 22 to the discharge port of the compressor body 16 . Refrigerant gas discharged from the compressor main body 16 to the discharge port 22 flows through the discharge flow path 26 . A suction passage 28 connects the suction port 24 to the suction port of the compressor body 16 . Refrigerant gas sucked into the compressor main body 16 from the suction port 24 flows through the suction passage 28 . Each of the discharge channel 26 and the suction channel 28 is internal piping of the compressor 12 provided within the compressor housing 38, and may be a flexible tube or a rigid tube.
　ストレージタンク３０は、コールドヘッド１４から圧縮機１２へと戻る低圧の冷媒ガスに含まれる脈動を除去するための容積として設けられている。ストレージタンク３０は、吸入流路２８に配置されている。 The storage tank 30 is provided as a volume for removing pulsation contained in the low pressure refrigerant gas returning from the cold head 14 to the compressor 12 . The storage tank 30 is arranged in the suction flow path 28 .
　冷媒ガスチャージポート３１は、極低温冷凍機１０に冷媒ガスを充填するための充填口として圧縮機筐体３８に設けられている。冷媒ガスチャージポート３１は、この実施の形態では、ストレージタンク３０と吸入ポート２４の間で吸入流路２８に接続されている。あるいは、冷媒ガスチャージポート３１は、ストレージタンク３０に接続されてもよい。冷媒ガスチャージポート３１は、通常は蓋で閉じられていてもよい。冷媒ガスを充填するとき、冷媒ガスチャージポート３１に冷媒ガスタンクが接続され、そこから冷媒ガスが冷媒ガスチャージポート３１を通じて圧縮機１２内に供給される。 The refrigerant gas charge port 31 is provided in the compressor housing 38 as a filling port for filling the cryogenic refrigerator 10 with refrigerant gas. Refrigerant gas charge port 31 is connected to suction channel 28 between storage tank 30 and suction port 24 in this embodiment. Alternatively, refrigerant gas charge port 31 may be connected to storage tank 30 . The refrigerant gas charge port 31 may normally be closed with a lid. When the refrigerant gas is charged, the refrigerant gas charge port 31 is connected to the refrigerant gas tank, and the refrigerant gas is supplied from there through the refrigerant gas charge port 31 into the compressor 12 .
　バイパス流路３２は、アドゾーバ２１で浄化された冷媒ガスがバイパス流路に流入するように、アドゾーバ２１に、またはアドゾーバ２１よりも下流で吐出流路２６に接続されている。この実施の形態では、バイパス流路３２は、アドゾーバ２１と吐出ポート２２の間で吐出流路２６に接続されている。また、バイパス流路３２は、ストレージタンク３０に接続され、それにより吐出流路２６を吸入流路２８に接続する。 The bypass flow path 32 is connected to the Adsorber 21 or to the discharge flow path 26 downstream of the Adsorber 21 so that the refrigerant gas purified by the Adsorber 21 flows into the bypass flow path. In this embodiment, the bypass channel 32 is connected to the discharge channel 26 between the adsorber 21 and the discharge port 22 . A bypass flow path 32 is also connected to the storage tank 30 , thereby connecting the discharge flow path 26 to the suction flow path 28 .
　バイパス流路３２は、極低温冷凍機１０を停止する際に高圧側と低圧側を均圧化するために設けられている。バイパス流路３２には、バイパス弁３３が設けられている。バイパス弁３３は、圧縮機１２の運転中（つまり圧縮機１２がオンのとき）には閉鎖され、バイパス流路３２を通じた冷媒ガス流れを遮断する。バイパス弁３３は、圧縮機１２を停止するとき（圧縮機１２をオンからオフに切り替えるとき）開放される。バイパス弁３３の開放により、吐出流路２６からバイパス流路３２を通じた吸入流路２８への冷媒ガスの流入が許容され、吐出流路２６と吸入流路２８の冷媒ガス圧力が均圧化される。バイパス弁３３は、常開型の開閉弁であってもよく、圧縮機１２への給電を停止したとき自然に開放されてもよい。 The bypass flow path 32 is provided to equalize the pressure on the high pressure side and the low pressure side when the cryogenic refrigerator 10 is stopped. A bypass valve 33 is provided in the bypass flow path 32 . Bypass valve 33 is closed during operation of compressor 12 (that is, when compressor 12 is on) to block refrigerant gas flow through bypass flow path 32 . Bypass valve 33 is opened when stopping compressor 12 (when switching compressor 12 from on to off). By opening the bypass valve 33, the refrigerant gas is allowed to flow from the discharge passage 26 to the suction passage 28 through the bypass passage 32, and the refrigerant gas pressures in the discharge passage 26 and the suction passage 28 are equalized. be. The bypass valve 33 may be a normally open on-off valve, and may be naturally opened when power supply to the compressor 12 is stopped.
　なお、バイパス流路３２には、バイパス弁３３と並列に流量制御弁が設けられてもよい。この流量制御弁を利用して、吐出流路２６と吸入流路２８の差圧が調整されてもよい。 A flow control valve may be provided in parallel with the bypass valve 33 in the bypass flow path 32 . The differential pressure between the discharge channel 26 and the suction channel 28 may be adjusted using this flow control valve.
　冷媒ガス冷却部３４およびオイル冷却部３６は、例えば冷却水などの冷却媒体を用いて圧縮機１２を冷却する冷却系を構成する。冷媒ガス冷却部３４は、吐出流路２６の上流部２６ａに配置され、圧縮機本体１６での冷媒ガスの圧縮に伴って生じる圧縮熱により加熱された高圧の冷媒ガスを冷却するために設けられている。冷媒ガス冷却部３４は、冷媒ガスと冷却媒体との熱交換により冷媒ガスを冷却する。また、オイル冷却部３６は、圧縮機本体１６から流出するオイルと冷却媒体との熱交換によりオイルを冷却する。冷却媒体は、外部から圧縮機１２に供給され、冷媒ガス冷却部３４とオイル冷却部３６を経て、圧縮機１２の外部に排出される。このようにして、圧縮機本体１６で生じる圧縮熱は、冷却媒体とともに圧縮機１２の外へと除去される。なお、冷却媒体は、例えばチラー（図示せず）により冷却され、再び供給されてもよい。 The refrigerant gas cooling unit 34 and the oil cooling unit 36 constitute a cooling system that cools the compressor 12 using a cooling medium such as cooling water. The refrigerant gas cooling part 34 is arranged in the upstream part 26 a of the discharge passage 26 and is provided to cool the high-pressure refrigerant gas heated by the heat of compression generated as the refrigerant gas is compressed in the compressor main body 16 . ing. The refrigerant gas cooling unit 34 cools the refrigerant gas by heat exchange between the refrigerant gas and the cooling medium. Further, the oil cooling portion 36 cools the oil by heat exchange between the oil flowing out from the compressor main body 16 and the cooling medium. A cooling medium is supplied to the compressor 12 from the outside, passes through the refrigerant gas cooling section 34 and the oil cooling section 36, and is discharged to the outside of the compressor 12. As shown in FIG. In this way, the heat of compression generated in the compressor body 16 is removed out of the compressor 12 along with the cooling medium. The cooling medium may be cooled by, for example, a chiller (not shown) and supplied again.
　圧縮機筐体３８には、圧縮機本体１６をはじめとして、吐出流路２６上のオイルセパレータ２０、アドゾーバ２１、吸入流路２８上のストレージタンク３０といった圧縮機１２の各構成要素が収容されている。冷媒ガス冷却部３４およびオイル冷却部３６も圧縮機筐体３８に収容されている。 Compressor housing 38 accommodates each component of compressor 12 such as compressor main body 16, oil separator 20 on discharge passage 26, adsorber 21, and storage tank 30 on intake passage 28. there is A refrigerant gas cooling portion 34 and an oil cooling portion 36 are also housed in the compressor housing 38 .
　また、極低温冷凍機１０は、コールドヘッド１４の室温部１４ａに高圧ポート４０と低圧ポート４１とを備える。高圧ポート４０は、高圧配管４２によって吐出ポート２２に接続され、低圧ポート４１は、低圧配管４３によって吸入ポート２４に接続されている。高圧配管４２と低圧配管４３は、圧縮機１２の外に配置される。通例、高圧配管４２と低圧配管４３は、フレキシブル管であるが、リジッド管であってもよい。 The cryogenic refrigerator 10 also includes a high pressure port 40 and a low pressure port 41 in the room temperature section 14 a of the cold head 14 . The high pressure port 40 is connected to the discharge port 22 by a high pressure pipe 42 and the low pressure port 41 is connected to the suction port 24 by a low pressure pipe 43 . The high pressure piping 42 and the low pressure piping 43 are arranged outside the compressor 12 . Typically, the high pressure pipe 42 and the low pressure pipe 43 are flexible pipes, but they may also be rigid pipes.
　極低温冷凍機１０は、極低温冷凍機１０のオンオフを切り替えるためのメインスイッチ５０を備えてもよい。メインスイッチ５０は、圧縮機１２に設置されてもよい。メインスイッチ５０がオンのとき、圧縮機１２とコールドヘッド１４が運転され、メインスイッチ５０がオフのとき、圧縮機１２とコールドヘッド１４の運転が停止される。メインスイッチ５０は、手動により操作可能であってもよい。それとともに、またはそれに代えて、メインスイッチ５０は、予め定められた条件に従って自動的に切り替えられてもよい。例えば、メインスイッチ５０は、予め定められたスケジュールに従って、極低温冷凍機１０をオンまたはオフに切り替えられてもよい。 The cryogenic refrigerator 10 may include a main switch 50 for switching the cryogenic refrigerator 10 on and off. The main switch 50 may be installed on the compressor 12 . When the main switch 50 is on, the compressor 12 and the cold head 14 are operated, and when the main switch 50 is off, the compressor 12 and the cold head 14 are stopped. The main switch 50 may be manually operable. Additionally or alternatively, the main switch 50 may be automatically switched according to predetermined conditions. For example, main switch 50 may turn cryocooler 10 on or off according to a predetermined schedule.
　上述のように、圧縮機本体１６は、固定された一定の冷媒ガス流量を吐出するものであってもよく、これは、圧縮機本体１６を駆動するモータを定速で（つまり一定の運転周波数で）運転することにより実現されてもよい。この場合、省エネルギーのために、メインスイッチ５０による極低温冷凍機１０のオンオフ切り替えが利用されてもよい。また、他の用途として、極低温冷凍機１０による冷却対象が極低温環境で使用される（例えば極低温に冷却した状態で使用されることで測定精度が向上される）センサである場合、極低温冷凍機１０の運転により発生する振動を抑制し更に測定精度を向上するために、このセンサによる測定時に極低温冷凍機１０がオフに切り替えられてもよい。 As noted above, the compressor body 16 may deliver a fixed, constant refrigerant gas flow rate, which forces the motor driving the compressor body 16 to operate at a constant speed (i.e., a constant operating frequency). in). In this case, on/off switching of the cryogenic refrigerator 10 by the main switch 50 may be used for energy saving. In addition, as another application, when the object to be cooled by the cryogenic refrigerator 10 is a sensor that is used in a cryogenic environment (for example, the measurement accuracy is improved by being used in a state of being cooled to a cryogenic temperature), The cryocooler 10 may be switched off during measurements by this sensor in order to suppress vibrations generated by the operation of the cryocooler 10 and further improve measurement accuracy.
　メインスイッチ５０がオンとされ、極低温冷凍機１０が運転されるとき、コールドヘッド１４から圧縮機１２に回収される冷媒ガスは、低圧ポート４１から低圧配管４３を通じて圧縮機１２の吸入ポート２４に流入する。冷媒ガスは、吸入流路２８上のストレージタンク３０を経て、圧縮機本体１６の吸入口へと回収される。 When the main switch 50 is turned on and the cryogenic refrigerator 10 is operated, the refrigerant gas recovered from the cold head 14 into the compressor 12 is supplied from the low pressure port 41 to the suction port 24 of the compressor 12 through the low pressure pipe 43. influx. The refrigerant gas passes through the storage tank 30 on the suction flow path 28 and is recovered to the suction port of the compressor main body 16 .
　冷媒ガスは、圧縮機本体１６によって圧縮され昇圧される。圧縮機本体１６の吐出口から送出される冷媒ガスは、吐出流路２６上の冷媒ガス冷却部３４で冷却され、その後オイルセパレータ２０およびアドゾーバ２１で浄化される。圧縮機本体１６で冷媒ガスに混入したオイルの大部分は、オイルセパレータ２０で分離されて圧縮機本体１６へと回収される。オイルセパレータ２０を通過した冷媒ガスは、アドゾーバ２１に供給され、冷媒ガスに残留しているガス状オイル成分がアドゾーバ２１に吸着され除去される。このとき、バイパス弁３３は閉鎖されているため、アドゾーバ２１から出た清浄な高圧の冷媒ガスは、バイパス流路３２ではなく、吐出ポート２２に向かう。 The refrigerant gas is compressed and pressurized by the compressor main body 16 . Refrigerant gas delivered from the discharge port of the compressor main body 16 is cooled by the refrigerant gas cooling portion 34 on the discharge passage 26 and then purified by the oil separator 20 and the adsorber 21 . Most of the oil mixed in the refrigerant gas in the compressor main body 16 is separated by the oil separator 20 and recovered to the compressor main body 16 . The refrigerant gas that has passed through the oil separator 20 is supplied to the adsorber 21, and the gaseous oil component remaining in the refrigerant gas is adsorbed by the adsorber 21 and removed. Since the bypass valve 33 is closed at this time, the clean high-pressure refrigerant gas coming out of the adsorber 21 goes to the discharge port 22 instead of the bypass flow path 32 .
　冷媒ガスは、吐出ポート２２から圧縮機１２を出て、高圧配管４２と高圧ポート４０を経てコールドヘッド１４の内部に供給される。コールドヘッド１４内での冷媒ガスの断熱膨張により、コールドヘッド１４の低温部１４ｂが冷却される。こうして低圧となった冷媒ガスは、再びコールドヘッド１４から圧縮機１２に回収される。 Refrigerant gas exits the compressor 12 through the discharge port 22 and is supplied to the interior of the cold head 14 via the high pressure pipe 42 and the high pressure port 40 . Due to the adiabatic expansion of the refrigerant gas inside the cold head 14, the low temperature portion 14b of the cold head 14 is cooled. The low-pressure refrigerant gas is recovered from the cold head 14 to the compressor 12 again.
　メインスイッチ５０がオフとされ、極低温冷凍機１０の運転が停止されるとき、上述のように、バイパス弁３３が開かれる。バイパス流路３２がアドゾーバ２１よりも下流で吐出流路２６に接続されているから、アドゾーバ２１によって浄化された高圧ガスがバイパス流路３２を通じて吐出流路２６から吸入流路２８に流入する。こうして、極低温冷凍機１０の高圧側と低圧側の冷媒ガス圧力が均圧化される。 When the main switch 50 is turned off and the operation of the cryogenic refrigerator 10 is stopped, the bypass valve 33 is opened as described above. Since the bypass flow path 32 is connected to the discharge flow path 26 downstream of the adsorber 21 , the high-pressure gas purified by the adsorber 21 flows from the discharge flow path 26 into the suction flow path 28 through the bypass flow path 32 . In this way, the refrigerant gas pressures on the high pressure side and the low pressure side of the cryogenic refrigerator 10 are equalized.
　実施の形態に係る極低温冷凍機１０におけるバイパス流路３２の利点を理解するために、ここで、比較例に係る極低温冷凍機を説明する。 In order to understand the advantage of the bypass flow path 32 in the cryogenic refrigerator 10 according to the embodiment, a cryogenic refrigerator according to a comparative example will now be described.
　図２は、比較例に係る極低温冷凍機１００を概略的に示す図である。この極低温冷凍機１００は、バイパス流路１３２の接続に関して上述の実施の形態と異なり、その余は同様である。図２に示されるように、比較例に係る極低温冷凍機１００の圧縮機１２では、バイパス流路１３２は、オイルセパレータ２０とアドゾーバ２１の間で吐出流路２６から分岐し、ストレージタンク３０に接続される。 FIG. 2 is a diagram schematically showing a cryogenic refrigerator 100 according to a comparative example. This cryogenic refrigerator 100 differs from the above-described embodiment with respect to the connection of the bypass flow path 132, and the remainder is the same. As shown in FIG. 2 , in the compressor 12 of the cryogenic refrigerator 100 according to the comparative example, the bypass flow path 132 branches from the discharge flow path 26 between the oil separator 20 and the adsorber 21 to the storage tank 30. Connected.
　本発明者は、比較例の極低温冷凍機１００では、コールドヘッド１４から圧縮機１２に回収される低圧冷媒ガスが流れる低圧側の冷媒ガス流路（例えば、吸入流路２８、低圧配管４３、冷媒ガスチャージポート３１）が時にオイルで汚染されることを発見した。 In the cryogenic refrigerator 100 of the comparative example, the low-pressure side refrigerant gas passage (for example, the suction passage 28, the low-pressure pipe 43, We have discovered that the refrigerant gas charge port 31) is sometimes contaminated with oil.
　本発明者の考察によると、このような汚染は、圧縮機１２をオフとするときのバイパス流路１３２を通じた均圧化に起因すると考えられる。 According to the inventor's consideration, such contamination is considered to be caused by pressure equalization through the bypass flow path 132 when the compressor 12 is turned off.
　バイパス弁３３が開くと、吐出流路２６からバイパス流路１３２を通じて吸入流路２８へと冷媒ガスが流れ込む。冷媒ガスの一部はバイパス流路１３２から圧縮機本体１６へと向かうが、バイパス流路１３２からの冷媒ガス流れの大半は、図２に破線の矢印で示すように、吸入流路２８を吸入ポート２４および冷媒ガスチャージポート３１に向かって逆流し、さらには低圧配管４３へと逆流しうる。これは、吸入流路２８から低圧配管４３を通じて低圧ポート４１に至る低圧側流路容積に比べて、圧縮機本体１６に向かう流路容積が小さいためである。 When the bypass valve 33 is opened, refrigerant gas flows from the discharge channel 26 through the bypass channel 132 into the intake channel 28 . A portion of the refrigerant gas flows from the bypass passage 132 toward the compressor body 16, but most of the refrigerant gas flow from the bypass passage 132 is sucked through the suction passage 28 as indicated by the dashed arrow in FIG. It can flow back to port 24 and refrigerant gas charge port 31 and back to low pressure line 43 . This is because the volume of the flow path toward the compressor main body 16 is smaller than the volume of the low-pressure side flow path from the suction flow path 28 to the low-pressure port 41 through the low-pressure pipe 43 .
　この逆流する冷媒ガスは、オイルセパレータ２０によってオイル分離されているが、アドゾーバ２１を経由していないので、ガス状オイル成分を（微量であるが）含みうる。そのため、長期の運転を通じてきわめて多数回の冷媒ガス逆流（例えば２５００回程度のオンオフ切替とそれに伴う均圧化および冷媒ガス逆流）を受けることにより、徐々にオイルが低圧側の冷媒ガス流路に蓄積され、汚染が進んだものと考えられる。汚染された場合には、流路内の洗浄や配管の交換など煩雑な保守作業を要し、手間や費用がかかる。 This backflowing refrigerant gas is oil-separated by the oil separator 20, but since it does not pass through the adsorber 21, it may contain a gaseous oil component (albeit in a very small amount). Therefore, oil gradually accumulates in the low-pressure side refrigerant gas flow path by receiving a very large number of refrigerant gas backflows (for example, about 2500 on-off switching and accompanying pressure equalization and refrigerant gas backflow) during long-term operation. It is considered that the contamination has progressed. In the case of contamination, troublesome maintenance work such as cleaning of the inside of the flow path and replacement of piping is required, which is time-consuming and costly.
　加えて、冷媒ガスチャージポート３１への逆流により、冷媒ガスチャージポート３１にオイルが溜まりうる。冷媒ガスを充填するために冷媒ガスチャージポート３１を開いたときオイルがガスとともに噴出し、周囲を汚すといった不都合も起こりうる。 In addition, oil may accumulate in the refrigerant gas charge port 31 due to backflow to the refrigerant gas charge port 31 . When the refrigerant gas charge port 31 is opened to charge the refrigerant gas, the oil may spout out together with the gas and contaminate the surroundings.
　なお、省エネルギーのためにインバータを搭載した圧縮機が極低温冷凍機に用いられることがあるが、この場合には圧縮機を運転しながら圧縮機の運転周波数がインバータにより制御されるから、圧縮機のオンオフ切替を頻繁に経験することは現実に極めて稀である。そのため、インバータ搭載型の圧縮機では、比較例のバイパス流路接続であっても、低圧側のオイル汚染は事実上発生しないとみなしうる。よって、上述の低圧側冷媒ガス流路のオイル汚染問題は、インバータを搭載する代わりに極低温冷凍機１０のオンオフ切替により省エネルギー性の向上を目指す上述の構成に特有であるといえる。 In some cases, a compressor equipped with an inverter is used in a cryogenic refrigerator for energy saving. In reality, it is extremely rare to experience frequent on/off switching. Therefore, in the inverter-mounted compressor, it can be considered that oil contamination on the low-pressure side does not actually occur even with the bypass flow path connection of the comparative example. Therefore, the problem of oil contamination in the low-pressure side refrigerant gas flow path described above can be said to be unique to the above-described configuration that aims to improve energy saving by switching the cryogenic refrigerator 10 on and off instead of installing an inverter.
　実施の形態に係る極低温冷凍機１０では、圧縮機１２をオフに切り替えたとき、アドゾーバ２１で浄化された冷媒ガスが吐出流路２６からバイパス流路３２を通じて吸入流路２８に流れることになる。冷媒ガスが低圧側の冷媒ガス流路に逆流したとしても、この冷媒ガスはアドゾーバ２１で浄化されているから、低圧側の冷媒ガス流路のオイル汚染は可能な限り避けられる。したがって、オイル汚染に起因する煩雑な保守作業や冷媒ガスチャージポート３１からのオイル噴出など上記で指摘した問題も解消または軽減される。 In the cryogenic refrigerator 10 according to the embodiment, when the compressor 12 is switched off, the refrigerant gas purified by the adsorber 21 flows from the discharge flow path 26 to the suction flow path 28 through the bypass flow path 32. . Even if the refrigerant gas flows back into the refrigerant gas passage on the low pressure side, the refrigerant gas is purified by the adsorber 21, so oil contamination in the refrigerant gas passage on the low pressure side is avoided as much as possible. Therefore, the above-mentioned problems such as troublesome maintenance work caused by oil contamination and oil spouting from the refrigerant gas charge port 31 can be eliminated or reduced.
　図３は、他の実施の形態に係る極低温冷凍機を概略的に示す図である。この極低温冷凍機１０は、冷媒ガスチャージポート３１とバイパス流路１３２に関して図１に示される実施の形態と異なり、その余は同様である。 FIG. 3 is a diagram schematically showing a cryogenic refrigerator according to another embodiment. This cryogenic refrigerator 10 differs from the embodiment shown in FIG. 1 with respect to the refrigerant gas charge port 31 and the bypass passage 132, and the rest is the same.
　冷媒ガスチャージポート３１は、圧縮機本体１６とストレージタンク３０との間で吸入流路２８に接続されている。 The refrigerant gas charge port 31 is connected to the suction flow path 28 between the compressor body 16 and the storage tank 30 .
　バイパス流路１３２は、図２に示される比較例と同様に、オイルセパレータ２０とアドゾーバ２１の間で吐出流路２６から分岐し、ストレージタンク３０に接続されている。なお、バイパス流路１３２は、ストレージタンク３０よりも上流で（つまり吸入ポート２４とストレージタンク３０の間で）吸入流路２８に接続されてもよい。 The bypass flow path 132 branches from the discharge flow path 26 between the oil separator 20 and the adsorber 21 and is connected to the storage tank 30, as in the comparative example shown in FIG. Note that the bypass flow path 132 may be connected to the intake flow path 28 upstream of the storage tank 30 (that is, between the intake port 24 and the storage tank 30).
　図３に示される実施の形態でも、均圧時にバイパス流路１３２を通じた吸入流路２８への冷媒ガスの逆流は起こりうる。しかしながら、図２に示される比較例とは異なり、冷媒ガスチャージポート３１への冷媒ガスの逆流は起こりにくくなる。これは、吸入流路２８から低圧配管４３を通じて低圧ポート４１に至る低圧側流路容積に比べて、冷媒ガスチャージポート３１への流路容積が小さいためである。冷媒ガスチャージポート３１への冷媒ガス逆流が抑えられることにより、冷媒ガスチャージポート３１へのオイル蓄積とそれによるオイル噴出を防止または緩和することができる。 Even in the embodiment shown in FIG. 3, backflow of the refrigerant gas to the suction flow path 28 through the bypass flow path 132 may occur during pressure equalization. However, unlike the comparative example shown in FIG. 2, reverse flow of the refrigerant gas to the refrigerant gas charge port 31 is less likely to occur. This is because the volume of the flow path to the refrigerant gas charge port 31 is smaller than the volume of the low pressure side flow path from the suction flow path 28 to the low pressure port 41 through the low pressure pipe 43 . By suppressing the refrigerant gas backflow to the refrigerant gas charge port 31, it is possible to prevent or reduce oil accumulation in the refrigerant gas charge port 31 and the resulting oil ejection.
　なお、図３に示される実施の形態において、バイパス流路１３２に代えて、図１に示されるバイパス流路３２が用いられてもよい。すなわち、バイパス流路３２は、アドゾーバ２１で浄化された冷媒ガスがバイパス流路に流入するように、アドゾーバ２１に、またはアドゾーバ２１よりも下流で吐出流路２６に接続されていてもよい。 It should be noted that in the embodiment shown in FIG. 3, the bypass channel 32 shown in FIG. 1 may be used instead of the bypass channel 132. That is, the bypass channel 32 may be connected to the adsorber 21 or downstream of the adsorber 21 to the discharge channel 26 so that the refrigerant gas purified by the adsorber 21 flows into the bypass channel.
　図４（ａ）および図４（ｂ）は、実施の形態に係るアドゾーバユニットを概略的に示す図である。図４（ａ）および図４（ｂ）に示されるアドゾーバユニットは、図１、図３に示される実施の形態におけるアドゾーバ２１として利用可能であり、圧縮機に着脱可能である。 FIGS. 4(a) and 4(b) are diagrams schematically showing an advertiser unit according to the embodiment. The adsorber unit shown in FIGS. 4(a) and 4(b) can be used as the adsorber 21 in the embodiment shown in FIGS. 1 and 3, and can be attached/detached to/from the compressor.
　図４（ａ）および図４（ｂ）に示されるように、アドゾーバユニットは、アドゾーバ本体２１ａと、未浄化の冷媒ガス５２が流入する冷媒ガス入口２１ｂと、アドゾーバ２１で浄化された冷媒ガス５４が流出する第１冷媒ガス出口２１ｃおよび第２冷媒ガス出口２１ｄとを備える。アドゾーバ本体２１ａは、筒状の容器に例えば活性炭などの吸着材を内蔵したものである。アドゾーバ本体２１ａは、極低温冷凍機１０の冷媒ガスを、冷媒ガス中のガス状オイル成分を吸着することにより浄化する。冷媒ガス入口２１ｂは、アドゾーバ本体２１ａの一端（例えば下端）に設けられ、第１冷媒ガス出口２１ｃおよび第１冷媒ガス出口２１ｃは、アドゾーバ本体２１ａの他端（例えば上端）に設けられている。 As shown in FIGS. 4(a) and 4(b), the adsorber unit includes an adsorber main body 21a, a refrigerant gas inlet 21b into which unpurified refrigerant gas 52 flows, and a refrigerant gas purified by the adsorber 21. 54 is provided with a first refrigerant gas outlet 21c and a second refrigerant gas outlet 21d. The adsorber main body 21a is a cylindrical container containing an adsorbent such as activated carbon. The adsorber main body 21a purifies the refrigerant gas of the cryogenic refrigerator 10 by adsorbing gaseous oil components in the refrigerant gas. The refrigerant gas inlet 21b is provided at one end (for example, the lower end) of the adsorber main body 21a, and the first refrigerant gas outlet 21c and the first refrigerant gas outlet 21c are provided at the other end (for example, the upper end) of the adsorber main body 21a.
　図４（ａ）に示されるアドゾーバユニットでは、第１冷媒ガス出口２１ｃおよび第２冷媒ガス出口２１ｄがアドゾーバ本体２１ａに設けられた分岐管に設けられている。また、図４（ｂ）に示されるアドゾーバユニットでは、第１冷媒ガス出口２１ｃおよび第２冷媒ガス出口２１ｄがそれぞれ別々にアドゾーバ本体２１ａに設けられている。 In the adsorber unit shown in FIG. 4(a), the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d are provided in branch pipes provided in the adsorber main body 21a. In addition, in the adsorber unit shown in FIG. 4B, the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d are separately provided in the adsorber main body 21a.
　冷媒ガス入口２１ｂは、図１から図３に示されるオイルセパレータ２０に接続される。バイパス流路３２が第１冷媒ガス出口２１ｃまたは第２冷媒ガス出口２１ｄのいずれかに接続され、吐出ポート２２がそれらのうち他方に接続される。冷媒ガス入口２１ｂ、第１冷媒ガス出口２１ｃおよび第２冷媒ガス出口２１ｄは、セルフシーリング・カップリングのような着脱可能な継手であってもよい。 The refrigerant gas inlet 21b is connected to the oil separator 20 shown in FIGS. 1 to 3. A bypass flow path 32 is connected to either the first refrigerant gas outlet 21c or the second refrigerant gas outlet 21d, and the discharge port 22 is connected to the other of them. The refrigerant gas inlet 21b, the first refrigerant gas outlet 21c and the second refrigerant gas outlet 21d may be detachable couplings such as self-sealing couplings.
　以上、本発明を実施例にもとづいて説明した。本発明は上記実施形態に限定されず、種々の設計変更が可能であり、様々な変形例が可能であること、またそうした変形例も本発明の範囲にあることは、当業者に理解されるところである。ある実施の形態に関連して説明した種々の特徴は、他の実施の形態にも適用可能である。組合せによって生じる新たな実施の形態は、組み合わされる実施の形態それぞれの効果をあわせもつ。 The present invention has been described above based on the examples. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that various design changes and modifications are possible, and that such modifications are within the scope of the present invention. By the way. Various features described in relation to one embodiment are also applicable to other embodiments. A new embodiment resulting from combination has the effects of each of the combined embodiments.
　上述の実施の形態では、バイパス流路３２は、圧縮機１２の内部に設けられているが、圧縮機１２の外に設けられてもよい。例えば、バイパス流路３２は、圧縮機筐体３８の外に配置され、高圧配管４２と低圧配管４３を接続してもよい。このようにしても、均圧時に、アドゾーバ２１によって浄化された高圧の冷媒ガスを低圧側に戻すことができる。汚染しにくくできる。低圧側の冷媒ガス流路のオイル汚染を回避できる。ここで、高圧配管４２は、吐出流路２６の一部であり、低圧配管４３は、吸入流路２８の一部であるとみなされてもよい。 Although the bypass flow path 32 is provided inside the compressor 12 in the above embodiment, it may be provided outside the compressor 12 . For example, the bypass flow path 32 may be located outside the compressor housing 38 and connect the high pressure line 42 and the low pressure line 43 . Even in this way, the high-pressure refrigerant gas purified by the adsorber 21 can be returned to the low-pressure side during pressure equalization. It is possible to prevent contamination. It is possible to avoid oil contamination of the refrigerant gas passage on the low pressure side. Here, the high pressure line 42 may be considered to be part of the discharge channel 26 and the low pressure line 43 to be part of the suction channel 28 .
　上述のように、極低温冷凍機１０による冷却対象が極低温環境で使用されるセンサである場合、このセンサによる測定時に極低温冷凍機１０がオフに切り替えられることがある。したがって、こうしたセンサ測定に伴う極低温冷凍機１０のオンオフ切替が実施される場合には、インバータ搭載型の圧縮機であっても低圧側のオイル汚染が発生する可能性を否定できない。そこで、実施の形態に係るアドゾーバ２１またはアドゾーバ２１よりも下流で吐出流路に接続されるバイパス流路３２は、インバータ搭載型の圧縮機に適用されてもよい。 As described above, when the object to be cooled by the cryogenic refrigerator 10 is a sensor used in a cryogenic environment, the cryogenic refrigerator 10 may be switched off during measurement by this sensor. Therefore, when the on/off switching of the cryogenic refrigerator 10 is performed in accordance with such sensor measurement, it cannot be denied that oil contamination on the low-pressure side may occur even with an inverter-mounted compressor. Therefore, the adsorber 21 according to the embodiment or the bypass flow path 32 connected to the discharge flow path downstream of the adsorber 21 may be applied to an inverter-mounted compressor.
　実施の形態にもとづき、具体的な語句を用いて本発明を説明したが、実施の形態は、本発明の原理、応用の一側面を示しているにすぎず、実施の形態には、請求の範囲に規定された本発明の思想を逸脱しない範囲において、多くの変形例や配置の変更が認められる。 Although the present invention has been described using specific terms based on the embodiment, the embodiment only shows one aspect of the principle and application of the present invention, and the embodiment does not include the claims. Many variations and rearrangements are permissible without departing from the spirit of the invention as defined in its scope.
　本発明は、極低温冷凍機用の圧縮機およびアドゾーバユニットの分野における利用が可能である。 The present invention can be used in the field of compressors and adsorber units for cryogenic refrigerators.
　１０　極低温冷凍機、　１２　圧縮機、　１６　圧縮機本体、　２１　アドゾーバ、　２１ａ　アドゾーバ本体、　２１ｂ　冷媒ガス入口、　２１ｃ　第１冷媒ガス出口、　２１ｄ　第２冷媒ガス出口、　２６　吐出流路、　２８　吸入流路、　３０　ストレージタンク、　３１　冷媒ガスチャージポート、　３２　バイパス流路。 10 Cryogenic refrigerator, 12 Compressor, 16 Compressor body, 21 Adsorber, 21a Adsorber body, 21b Refrigerant gas inlet, 21c First refrigerant gas outlet, 21d Second refrigerant gas outlet, 26 Discharge flow path, 28 Suction flow path , 30 Storage tank, 31 Refrigerant gas charge port, 32 Bypass channel.

Claims (7)

  1. 　極低温冷凍機の冷媒ガスを圧縮するオイル潤滑式の圧縮機本体と、
    　前記圧縮機本体に接続され、前記圧縮機本体に吸入される冷媒ガスが流れる吸入流路と、
    　前記圧縮機本体に接続され、前記圧縮機本体から吐出される冷媒ガスが流れる吐出流路と、
    　前記吐出流路を前記吸入流路に接続するバイパス流路と、
    　前記吐出流路に設けられ、冷媒ガス中のガス状オイル成分を吸着することにより冷媒ガスを浄化するアドゾーバと、を備え、
    　前記バイパス流路は、前記アドゾーバで浄化された冷媒ガスが前記バイパス流路に流入するように、前記アドゾーバに、または前記アドゾーバよりも下流で前記吐出流路に接続されていることを特徴とする極低温冷凍機用の圧縮機。     An oil-lubricated compressor main body that compresses the refrigerant gas of the cryogenic refrigerator,
    a suction passage connected to the compressor main body through which refrigerant gas sucked into the compressor main body flows;
    a discharge passage connected to the compressor main body through which refrigerant gas discharged from the compressor main body flows;
    a bypass flow path connecting the discharge flow path to the suction flow path;
    an adsorber that is provided in the discharge flow path and purifies the refrigerant gas by adsorbing gaseous oil components in the refrigerant gas,
    The bypass channel is connected to the adsorber or downstream of the adsorber to the discharge channel so that the refrigerant gas purified by the adsorber flows into the bypass channel. Compressors for cryogenic refrigerators.
  2. 　前記アドゾーバは、未浄化の冷媒ガスが流入する冷媒ガス入口と、前記アドゾーバで浄化された冷媒ガスが流出する第１冷媒ガス出口および第２冷媒ガス出口と、を備え、
    　前記バイパス流路が、前記第１冷媒ガス出口または前記第２冷媒ガス出口のいずれかに接続されていることを特徴とする請求項１に記載の極低温冷凍機用の圧縮機。     The Adsorber has a refrigerant gas inlet into which unpurified refrigerant gas flows, and a first refrigerant gas outlet and a second refrigerant gas outlet into which refrigerant gas purified by the Adsorber flows out,
    2. A compressor for a cryogenic refrigerator according to claim 1, wherein said bypass passage is connected to either said first refrigerant gas outlet or said second refrigerant gas outlet.
  3. 　前記吸入流路には、ストレージタンクが設けられ、前記バイパス流路は、前記ストレージタンクに、または前記ストレージタンクよりも上流で前記吸入流路に接続されていることを特徴とする請求項１または２に記載の極低温冷凍機用の圧縮機。 2. The intake channel is provided with a storage tank, and the bypass channel is connected to the storage tank or to the intake channel upstream of the storage tank. 3. A compressor for a cryogenic refrigerator according to 2.
  4. 　前記圧縮機本体と前記ストレージタンクとの間で前記吸入流路に接続された冷媒ガスチャージポートをさらに備えることを特徴とする請求項３に記載の極低温冷凍機用の圧縮機。 The compressor for a cryogenic refrigerator according to claim 3, further comprising a refrigerant gas charge port connected to the suction flow path between the compressor body and the storage tank.
  5. 　前記バイパス流路は、極低温冷凍機を停止する際に前記吐出流路と前記吸入流路を均圧化するバイパス弁を備え、
    　前記バイパス弁は、前記圧縮機の運転中に閉じ、前記圧縮機を停止するとき開くように構成されていることを特徴とする請求項１から４のいずれかに記載の極低温冷凍機用の圧縮機。     The bypass flow path includes a bypass valve that equalizes the pressure of the discharge flow path and the suction flow path when the cryogenic refrigerator is stopped,
    5. The cryogenic refrigerator according to any one of claims 1 to 4, wherein the bypass valve is configured to be closed during operation of the compressor and open when the compressor is stopped. compressor.
  6. 　極低温冷凍機の冷媒ガスを、冷媒ガス中のガス状オイル成分を吸着することにより浄化するアドゾーバ本体と、
    　前記アドゾーバ本体に設けられ、未浄化の冷媒ガスが流入する冷媒ガス入口と、
    　前記アドゾーバ本体に設けられ、前記アドゾーバ本体で浄化された冷媒ガスが流出する第１冷媒ガス出口および第２冷媒ガス出口と、を備えることを特徴とするアドゾーバユニット。     an adsorber body that purifies the refrigerant gas of the cryogenic refrigerator by adsorbing gaseous oil components in the refrigerant gas;
    a refrigerant gas inlet provided in the adsorber body and into which unpurified refrigerant gas flows;
    An adsorber unit, comprising: a first refrigerant gas outlet and a second refrigerant gas outlet, which are provided in the adsorber body and through which refrigerant gas purified by the adsorber body flows out.
  7. 　極低温冷凍機の冷媒ガスを圧縮するオイル潤滑式の圧縮機本体と、
    　前記圧縮機本体に接続され、前記圧縮機本体に吸入される冷媒ガスが流れる吸入流路と、
    　前記圧縮機本体に接続され、前記圧縮機本体から吐出される冷媒ガスが流れる吐出流路と、
    　前記吐出流路を前記吸入流路に接続するバイパス流路と、を備え、
    　前記吸入流路には、ストレージタンクが設けられ、前記バイパス流路は、前記ストレージタンクに、または前記ストレージタンクよりも上流で前記吸入流路に接続され、
    　前記圧縮機本体と前記ストレージタンクとの間で前記吸入流路に接続された冷媒ガスチャージポートをさらに備えることを特徴とする極低温冷凍機用の圧縮機。     An oil-lubricated compressor main body that compresses the refrigerant gas of the cryogenic refrigerator,
    a suction passage connected to the compressor main body through which refrigerant gas sucked into the compressor main body flows;
    a discharge passage connected to the compressor main body through which refrigerant gas discharged from the compressor main body flows;
    a bypass flow path connecting the discharge flow path to the suction flow path,
    A storage tank is provided in the suction flow path, and the bypass flow path is connected to the storage tank or to the suction flow path upstream of the storage tank,
    A compressor for a cryogenic refrigerator, further comprising a refrigerant gas charge port connected to the suction passage between the compressor body and the storage tank.
PCT/JP2022/004513 2021-02-22 2022-02-04 Compressor for ultra-low-temperature freezer, and adsorber unit WO2022176652A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024070359A1 (en) * 2022-09-28 2024-04-04 株式会社村田製作所 Vehicular air conditioning device

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Publication number Priority date Publication date Assignee Title
JPS62171762U (en) * 1986-04-17 1987-10-31
JPH094932A (en) * 1995-06-16 1997-01-10 Mitsubishi Electric Corp Deep freezer
JP2015137779A (en) * 2014-01-21 2015-07-30 株式会社デンソー heat pump cycle

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62171762U (en) * 1986-04-17 1987-10-31
JPH094932A (en) * 1995-06-16 1997-01-10 Mitsubishi Electric Corp Deep freezer
JP2015137779A (en) * 2014-01-21 2015-07-30 株式会社デンソー heat pump cycle

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024070359A1 (en) * 2022-09-28 2024-04-04 株式会社村田製作所 Vehicular air conditioning device

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