WO2015025515A1 - Refrigeration device - Google Patents

Refrigeration device Download PDF

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Publication number
WO2015025515A1
WO2015025515A1 PCT/JP2014/004235 JP2014004235W WO2015025515A1 WO 2015025515 A1 WO2015025515 A1 WO 2015025515A1 JP 2014004235 W JP2014004235 W JP 2014004235W WO 2015025515 A1 WO2015025515 A1 WO 2015025515A1
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WO
WIPO (PCT)
Prior art keywords
oil
compressor
refrigerant
lubricating oil
return passage
Prior art date
Application number
PCT/JP2014/004235
Other languages
French (fr)
Japanese (ja)
Inventor
俊之 外山
上川　隆司
洋平 西出
Original Assignee
ダイキン工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Publication of WO2015025515A1 publication Critical patent/WO2015025515A1/en

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Classifications

    • 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
    • F25B31/00—Compressor arrangements
    • F25B31/002—Lubrication
    • F25B31/004—Lubrication oil recirculating arrangements
    • 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
    • F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
    • F25B2341/001—Ejectors not being used as compression device
    • F25B2341/0016—Ejectors for creating an oil recirculation
    • 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
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2519—On-off valves
    • 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
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/03—Oil level

Definitions

  • the present invention relates to a refrigeration apparatus having an oil separator that separates lubricating oil contained in a refrigerant.
  • a refrigeration apparatus having a refrigerant circuit that performs a refrigeration cycle by circulating refrigerant is known.
  • This type of refrigeration apparatus is widely used in, for example, a refrigerator for cooling a refrigerator that stores food or the like, an air conditioner that cools and heats a room, and the like.
  • the refrigerant discharged from the compressor contains lubricating oil used for lubrication in the compressor.
  • the lubricating oil is recovered by the oil separator and returned to the compressor.
  • the amount of lubricating oil flowing out from the compressor is estimated, and when it is determined that the oil level of the lubricating oil stored in the compressor has dropped below a predetermined height, the lubricating oil is lubricated in the compressor.
  • Control of returning oil is known.
  • Patent Document 1 describes that an electromagnetic valve of an oil return pipe that returns lubricating oil to a compressor is controlled according to conditions such as refrigerant pressure, temperature, and motor drive current frequency.
  • An object of the present invention is to reliably suppress the refrigerant concentration in the lubricating oil so that the compressor can be sufficiently lubricated.
  • 1st aspect of this indication is a refrigerating apparatus which has a refrigerant circuit (1) containing a compressor (10), and circulates a refrigerant
  • the refrigerant concentration sensor (19) that outputs a signal corresponding to the refrigerant concentration in the oil, the on-off valve (89) provided in the emergency oil return passage (88), and the output signal of the refrigerant concentration sensor (19) And a controller (6) for controlling the on-off valve (
  • the oil separator (80) is formed below the normal oil outlet (81) connected to the normal oil return passage (86), and the emergency oil return passage (81). And an emergency oil outlet (82) connected to (88).
  • the controller (6) opens the on-off valve (89) when the output signal of the refrigerant concentration sensor (19) indicates that the refrigerant concentration in the lubricating oil in the oil reservoir (18) is greater than a predetermined value. To control.
  • the compressor (10) has a refrigerant concentration sensor (19). For this reason, it is possible to know the refrigerant concentration in the lubricating oil in the oil sump (18) more accurately than when estimating the refrigerant concentration in the lubricating oil from the operating state.
  • the controller (6) opens the on-off valve (89) based on the output of the refrigerant concentration sensor (19). ) Can be immediately returned to the compressor (10).
  • the refrigerant concentration in the lubricating oil in the oil reservoir (18) decreases, and the viscosity of the lubricating oil increases. That is, according to this refrigeration apparatus, the refrigerant concentration in the lubricating oil can be suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing.
  • the emergency oil outlet (82) connected to the emergency oil return passage (88) is connected to the normal oil outlet (81) connected to the normal oil return passage (86). Formed below. For this reason, the lubricating oil that cannot be taken out from the normal oil outlet (81) but can be taken out from the emergency oil outlet (82) can be secured as the emergency lubricating oil. Therefore, in an emergency, this lubricating oil can be reliably returned to the compressor.
  • the compressor (10) in the first aspect, includes a suction pipe (16) into which a refrigerant flows.
  • the emergency oil return passage (88) is connected to the suction pipe (16) of the compressor (10).
  • the emergency oil return passage (88) is connected to the suction pipe (16) of the compressor (10), an opening for oil return is provided in the compressor (10). There is no need, and the lubricating oil can be easily returned to the compressor (10).
  • the compressor (10) in the second aspect, includes a suction portion (28) that sucks lubricating oil into the high-pressure space of the compressor (10).
  • the normal oil return passage (86) is connected to the suction part (28).
  • the compressor (10) has a suction part (28) that sucks lubricating oil into the high-pressure space. For this reason, the lubricating oil flowing through the normal oil return passage (86) can be directly returned to the high-pressure space. Even if the lubricating oil or refrigerant returns to the high-pressure space, the performance of the compressor (10) is hardly affected, and therefore it is not necessary to have a mechanism for adjusting the flow rate of the lubricating oil in the normal oil return passage (86). Therefore, cost reduction can be achieved.
  • the refrigeration apparatus further includes a control mechanism (87) provided in the normal oil return passage (86).
  • the normal oil return passage (86) is connected to the suction pipe (16) of the compressor (10), and the controller (6) is based on an output signal of the refrigerant concentration sensor (19). The flow rate of the lubricating oil in the normal oil return passage (86) is controlled.
  • the controller (6) controls the lubricating oil flow rate in the normal oil return passage (86) based on the output signal of the refrigerant concentration sensor (19). The accuracy of control for returning the lubricating oil from 80) to the compressor (10) using the normal oil return passage (86) is increased.
  • the compressor (10) has an oil return port (14) communicating with a high-pressure space of the compressor (10), and the emergency oil return
  • the passage (88) is connected to the oil return port (14), and the emergency oil outlet (82) of the oil separator (80) is disposed at a position higher than the oil return port (14). ing.
  • the lubricating oil is returned to the high pressure space in the compressor (10) from the high pressure oil separator (80) through the emergency oil return passage (88) by gravity. For this reason, the amount of lubricating oil in the oil reservoir (18) can be recovered quickly, and the refrigerant concentration in the lubricating oil in the oil reservoir (18) can be quickly reduced. Further, there is no reduction in efficiency that occurs when the lubricating oil is returned to the low-pressure space on the suction side.
  • the compressor (10) includes a suction portion (28) that sucks lubricating oil into a high-pressure space of the compressor (10), and the normal oil
  • the return passage (86) is connected to the suction part (28).
  • the compressor (10) has the suction portion (28) that sucks the lubricating oil into the high-pressure space. For this reason, the lubricating oil flowing through the normal oil return passage (86) can be directly returned to the high-pressure space. Even if the lubricating oil or refrigerant returns to the high-pressure space, the performance of the compressor (10) is hardly affected. Therefore, it is not necessary to have a mechanism for adjusting the flow rate of the lubricating oil in the normal oil return passage (86). Cost reduction can be achieved.
  • the refrigerant concentration sensor (19) is a capacitance type sensor.
  • the refrigerant concentration sensor (19) is a capacitance type sensor, a signal corresponding to the refrigerant concentration in the lubricating oil in the oil reservoir (18) of the compressor (10). Can be easily obtained.
  • the refrigerant concentration in the lubricating oil can be reliably suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing. Therefore, the compressor can be more reliably lubricated, and the reliability of the compressor and the refrigeration apparatus having the compressor can be improved.
  • FIG. 1 is a refrigerant circuit diagram illustrating a configuration example of a refrigerant circuit of a refrigeration apparatus according to an embodiment of the present invention.
  • FIG. 2 is a piping system diagram related to the compressor and oil separator of FIG.
  • FIG. 3 is a block diagram relating to the control of the valve of FIG.
  • FIG. 4 is a piping system diagram regarding the compressor and the oil separator of the refrigeration apparatus according to Modification 1 of the present embodiment.
  • FIG. 5 is a longitudinal sectional view showing an example of the structure of the ejector.
  • FIG. 6 is a piping system diagram related to the compressor and the oil separator of the refrigeration apparatus according to the second modification of the present embodiment.
  • flow rate indicates an amount per unit time.
  • FIG. 1 is a refrigerant circuit diagram illustrating a configuration example of a refrigerant circuit (1) of a refrigeration apparatus (100) according to an embodiment of the present invention.
  • the refrigeration apparatus (100) has a refrigerant circuit (1) and performs a refrigeration cycle by circulating refrigerant in the refrigerant circuit (1).
  • the refrigerant circuit (1) in FIG. 1 is a refrigerant circuit that performs a vapor compression refrigeration cycle, and includes a compressor (10), an oil separator (80), a condenser (2), and an expansion valve (3). And an evaporator (4).
  • the refrigerant circuit (1) is a closed circuit in which the compressor (10), oil separator (80), condenser (2), expansion valve (3), and evaporator (4) are connected in this order by refrigerant piping. is there.
  • the refrigeration apparatus (100) is also used for an air conditioner or the like.
  • FIG. 2 is a piping system diagram related to the compressor (10) and the oil separator (80) of FIG.
  • the compressor (10) is a rotary compressor, for example, a scroll compressor as shown in FIG.
  • the compressor (10) of FIG. 2 has a casing (15), a compression mechanism (20), an electric motor (50), and a drive shaft (60).
  • the casing (15) accommodates a compression mechanism (20), an electric motor (50), a drive shaft (60), and the like.
  • the drive shaft (60) is arranged in a posture extending in the vertical direction, and connects the compression mechanism (20) and the electric motor (50).
  • the casing (15) is provided with a suction pipe (16) and a discharge pipe (17).
  • the suction pipe (16) passes through the top of the casing (15) and opens into the upper space (11) above the compression mechanism (20) in the casing (15).
  • the suction pipe (16) is connected to the evaporator (4), and the refrigerant from the evaporator (4) flows into the suction pipe (16).
  • the discharge pipe (17) penetrates the side surface of the casing (15) and opens into the lower space (12) below the compression mechanism (20) in the casing (15).
  • the compression mechanism (20) compresses the refrigerant sucked from the low pressure upper space (11) and discharges it to the high pressure lower space (12).
  • the discharge pipe (17) is connected to the condenser (2).
  • Lubricating oil for example, refrigerating machine oil
  • an oil sump (18) is formed in the casing (15).
  • the oil supply passage extending in the axial direction is formed inside the drive shaft (60).
  • An oil supply pump is attached to the lower end of the oil supply passage.
  • the oil supply pump is, for example, a trochoid pump, but is not limited thereto.
  • the oil supply pump draws lubricating oil from the oil reservoir (18) and supplies it to the oil supply passage.
  • Lubricating oil is supplied to the compression mechanism (20) and the bearing of the drive shaft (60) and used for lubrication thereof. After being used for lubrication, most of the lubricant returns to the sump (18).
  • the compressor (10) has a refrigerant concentration sensor (19) in the casing (15).
  • the refrigerant concentration sensor (19) is disposed at the bottom of the casing (15) so as to be immersed in the lubricating oil in the oil reservoir (18) of the compressor (10). It is desirable that the refrigerant concentration sensor (19) be arranged at a low position in such a direction that the refrigerant concentration sensor (19) is lowered so as not to be affected by the change in the height of the lubricating oil surface. .
  • the refrigerant concentration sensor (19) may be in contact with the bottom of the casing (15) or may not be in contact therewith.
  • the refrigerant concentration sensor (19) outputs a signal corresponding to the refrigerant concentration in the lubricating oil in the oil reservoir (18).
  • the refrigerant concentration sensor (19) is, for example, a capacitance type sensor, and outputs a signal corresponding to the capacitance between the two electrodes. Since the capacitance between the electrodes changes according to the refrigerant concentration in the lubricating oil, the refrigerant concentration can be measured.
  • the refrigerant compressed by the compression mechanism (20) is discharged from the discharge pipe (17) and supplied to the oil separator (80).
  • Lubricating oil is mixed in the discharged refrigerant.
  • the oil separator (80) separates and stores the lubricating oil from the refrigerant, and discharges the refrigerant to the condenser (2).
  • the stored lubricating oil forms an oil reservoir (85) in the oil separator (80).
  • the refrigeration apparatus (100) has a normal oil return passage (86), a control mechanism (87), an emergency oil return passage (88), and an on-off valve (89) as shown in FIG.
  • the oil separator (80) has a normal oil outlet (81) and an emergency oil outlet (82).
  • the oil outlet (81) is formed so as to penetrate the side surface of the oil separator (80).
  • the emergency oil outlet (82) is formed below the normal oil outlet (81), for example, so as to penetrate the bottom of the oil separator (80).
  • Both the normal oil return passage (86) and the emergency oil return passage (88) return the lubricating oil stored in the oil separator (80) to the compressor (10).
  • the normal oil outlet (81) is connected to one end of the normal oil return passage (86).
  • the emergency oil outlet (82) is connected to one end of the emergency oil return passage (88).
  • the other end of the normal oil return passage (86) is connected to the suction pipe (16), for example, via a pipe connecting the evaporator (4) and the suction pipe (16).
  • the other end of the emergency oil return passageway (88) is also connected to the suction pipe (16) via, for example, a pipe connecting the evaporator (4) and the suction pipe (16).
  • the control mechanism (87) is normally provided in the oil return passage (86), and the on-off valve (89) is provided in the emergency oil return passage (88).
  • the control mechanism (87) for example, an electric valve or a solenoid valve (open / close valve) is used.
  • the lubricating oil flow rate of the normal oil return passageway (86) is controlled only by the motor-operated valve or the electromagnetic valve, the combination of any of these valves and the capillary, or only the capillary.
  • FIG. 3 is a block diagram relating to the control of the valve of FIG.
  • the refrigeration apparatus (100) has a controller (6).
  • the controller (6) controls the control mechanism (87) and the on-off valve (89) based on the output signal of the refrigerant concentration sensor (19). More specifically, for example, the controller (6) increases the opening of the motor-operated valve as the control mechanism (87) as the refrigerant concentration in the lubricating oil in the oil sump (18) of the compressor (10) increases.
  • the solenoid valve as the control mechanism (87) is opened to increase the flow rate of the lubricating oil in the normal oil return passage (86).
  • the controller (6) opens the on-off valve (89) when the output signal of the refrigerant concentration sensor (19) indicates that the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than a predetermined value. Control. This predetermined value is larger than the reference value. When the refrigerant concentration in the lubricating oil in the oil reservoir (18) reaches the predetermined value or a value sufficiently lower than the predetermined value, the controller (6) closes the on-off valve (89).
  • the compression mechanism (20) is rotationally driven by the electric motor (50).
  • the compression mechanism (20) compresses the refrigerant sucked from the suction pipe (16) and discharges it into the casing (15).
  • lubricating oil is supplied from the oil sump (18) in the casing (15) to the compression mechanism (20).
  • the lubricating oil supplied to the compression mechanism (20) is used for lubrication of the compression mechanism (20)
  • a part of the lubricating oil is discharged into the internal space of the casing (15) together with the compressed refrigerant.
  • Lubricating oil discharged together with the refrigerant from the compression mechanism (20) is a gap formed in the upper and lower spaces of the electric motor (50) and between the rotor and the stator of the electric motor (50), and the stator and casing ( Part of it is separated from the refrigerant while passing through the gap formed during 15).
  • the lubricating oil separated from the refrigerant in the casing (15) flows down to the oil reservoir (18).
  • the lubricating oil that has not been separated from the refrigerant flows out of the compressor (10) through the discharge pipe (17) together with the refrigerant.
  • the oil separator (80) separates and stores the lubricating oil from the refrigerant, and discharges the refrigerant to the condenser (2).
  • the refrigerant dissipates heat in the condenser (2) and flows into the evaporator (4) through the expansion valve (3).
  • the refrigerant flowing in absorbs heat from the surrounding air and evaporates to cool the air.
  • the low-pressure refrigerant discharged from the evaporator (4) flows into the suction pipe (16) of the compressor (10).
  • the controller (6) operates as an electric motor as the control mechanism (87) as the refrigerant concentration in the lubricating oil in the oil reservoir (18) of the compressor (10) increases.
  • the electromagnetic valve as the control mechanism (87) is opened. High pressure refrigerant flows from the compressor (10) into the oil separator (80), and the inside of the oil separator (80) is at high pressure.
  • the suction pipe (16) of the compressor (10) communicates with the low pressure upper space (11) of the compressor (10). Therefore, when the motor-operated valve or solenoid valve as the control mechanism (87) is opened, the lubricating oil in the oil reservoir (85) of the oil separator (80) passes through the normal oil return passage (86) and the compressor (10). Into the suction pipe (16).
  • the controller (6) opens the on-off valve (89) based on the output signal of the refrigerant concentration sensor (19). Then, the lubricating oil in the oil reservoir (85) of the oil separator (80) flows into the suction pipe (16) of the compressor (10) through the emergency oil return passage (88). Then, the ratio of the lubricating oil in the oil sump (18) of the compressor (10) increases, the refrigerant concentration decreases, and the viscosity of the lubricating oil increases.
  • the compressor (10) has a refrigerant concentration sensor (19). For this reason, the refrigerant
  • the controller (6) opens the on-off valve (89) based on the output of the refrigerant concentration sensor (19). ) Can be immediately returned to the compressor (10).
  • the refrigerant concentration in the lubricating oil in the oil reservoir (18) decreases, and the viscosity of the lubricating oil increases. That is, according to the refrigeration apparatus of this embodiment, the refrigerant concentration in the lubricating oil can be reliably suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing.
  • controller (6) controls the motor operated valve and electromagnetic valve as the control mechanism (87) based on the output of the refrigerant concentration sensor (19). For this reason, the accuracy of control for returning the lubricating oil from the oil separator (80) to the compressor (10) using the normal oil return passage (86) is increased.
  • the emergency oil outlet (82) connected to the emergency oil return passage (88) is connected to the normal oil outlet (81) connected to the normal oil return passage (86). Formed below. For this reason, lubricating oil that cannot be taken out from the normal oil outlet (81) but can be taken out from the emergency oil outlet (82) can be secured as an emergency lubricating oil. The oil can be reliably returned to the compressor (10).
  • the viscosity of the lubricating oil can be prevented from excessively decreasing.
  • the compressor (10) can be more reliably lubricated, and the reliability of the compressor (10) and the refrigeration apparatus (100) having the compressor (10) can be improved.
  • FIG. 4 is a piping system diagram related to the compressor (10) and the oil separator (80) of the refrigeration apparatus (100) according to the first modification of the present embodiment.
  • the compressor (10) has an oil suction port (13) for sucking lubricating oil.
  • the normal oil return passageway (86) is connected to the oil suction port (13) instead of the suction pipe (16), and the control mechanism (87) is omitted.
  • the compressor (10) has an ejector (28) as a suction portion that sucks lubricating oil into the high-pressure space of the compressor (10).
  • the refrigeration apparatus (100) according to the first modification is configured in substantially the same manner as the refrigeration apparatus (100) of the embodiment described with reference to FIGS.
  • FIG. 5 is a longitudinal sectional view showing an example of the structure of the ejector (28).
  • the ejector (28) constitutes a part of the housing (25) in the compressor (10), for example.
  • the normal oil return passage (86) is connected to the connection (28C) of the ejector (28) via the oil suction port (13), and the normal oil return passage (86) is connected to the connection (28C). It communicates with the passage (28D).
  • the high-pressure refrigerant discharged from the compression mechanism (20) flows into the internal flow path (28E).
  • the refrigerant that has flowed into the internal flow path (28E) is partly converted into velocity energy in the nozzle portion (28A), is accelerated as the pressure decreases, and is jetted from the nozzle portion (28A). Due to the pressure drop of the refrigerant in the nozzle portion (28A), the lubricating oil in the normal oil return passage (86) is sucked into the internal flow path (28E) through the communication passage (28D) of the connection portion (28C). .
  • the lubricating oil in the normal oil return passage (86) is sucked and joined by the refrigerant injected from the nozzle portion (28A). Part of the velocity energy of the merged refrigerant and lubricating oil is converted to pressure energy in the enlarged diameter portion (28B), decelerates and the pressure rises, and flows out from the ejector (28) to the lower space (12). .
  • the controller (6) opens and closes the open / close valve based on the output of the refrigerant concentration sensor (19), as in the refrigeration apparatus (100) of FIG. Open (89). For this reason, lubricating oil can be immediately returned from the oil separator (80) to the compressor (10), and the reliability of the compressor (10) and the refrigeration apparatus (100) can be improved.
  • the lubricating oil in the normal oil return passage (86) may be returned to the lower space (12) of the compressor (10) by using a pump or the like as a suction portion instead of the ejector (28).
  • the lubricating oil flowing through the normal oil return passage (86) is directly returned to the high pressure lower space (12) in the compressor (10). Even if a large amount of lubricating oil or refrigerant returns to the lower space (12), it hardly affects the performance of the compressor (10), so a control mechanism that adjusts the lubricating oil flow rate in the normal oil return passage (86) (87) becomes unnecessary. Further, when the ejector (28) is provided, it is not necessary to provide a boosting means such as a pump. Therefore, the lubricating oil in the oil separator (80) can be appropriately returned to the compressor (10) at low cost.
  • the volumetric efficiency is reduced without affecting the degree of superheat on the suction side. Does not occur. For this reason, it is possible to achieve both high-efficiency operation and improved reliability.
  • FIG. 6 is a piping diagram related to the compressor (10) and the oil separator (80) of the refrigeration apparatus (100) according to the second modification of the present embodiment.
  • the compressor (10) has an oil return port (14) communicating with a lower space (12) that is a high-pressure space of the compressor (10).
  • the emergency oil return passageway (88) is connected to the oil return port (14) instead of the suction pipe (16).
  • the emergency oil outlet (82) of the oil separator (80) is disposed at a position higher than the oil return port (14).
  • the refrigeration apparatus (100) according to the second modification is configured in substantially the same manner as the refrigeration apparatus (100) according to the first modification described with reference to FIG.
  • the lubricating oil in an emergency when the refrigerant concentration in the lubricating oil in the oil reservoir (18) is larger than a predetermined value, the lubricating oil passes through the emergency oil return passage (88) and passes through the high-pressure oil separator ( 80) is returned to the high pressure lower space (12) in the compressor (10) by gravity.
  • the lubricating oil that has returned to the lower space (12) is immediately added to the oil sump (18), so the amount of lubricating oil in the oil sump (18) quickly recovers and the refrigerant concentration in the lubricating oil in the oil sump (18) is restored. Can be quickly reduced.
  • the present invention is useful for a refrigeration apparatus having an oil separator.

Abstract

The present invention definitively suppresses the concentration of a coolant in a lubricating oil, and is capable of sufficiently lubricating a compressor. This refrigeration device has: an emergency oil-return channel (88) for returning a lubricating oil stored in an oil separator (80) to a compressor (10); a coolant-concentration sensor (19) for outputting a signal corresponding to the coolant concentration in the lubricating oil in the oil reservoir (18) of the compressor (10); an opening/closing valve (89) provided in the emergency oil-return channel (88); and a controller (6). The oil separator (80) has an emergency oil-discharge port (82) connected to the emergency oil-return channel (88), and formed below the normal oil-discharge port (81). The controller (6) opens the opening/closing valve (89) when the coolant concentration is greater than a prescribed value.

Description

冷凍装置Refrigeration equipment
　本発明は、冷媒に含まれる潤滑油を分離する油分離器を有する冷凍装置に関する。 The present invention relates to a refrigeration apparatus having an oil separator that separates lubricating oil contained in a refrigerant.
　冷媒を循環させて冷凍サイクルを行う冷媒回路を備える冷凍装置が知られている。この種の冷凍装置は、例えば、食品等を貯蔵する冷蔵庫を冷却するための冷凍機や、室内の冷暖房を行う空調機などに広く利用されている。 A refrigeration apparatus having a refrigerant circuit that performs a refrigeration cycle by circulating refrigerant is known. This type of refrigeration apparatus is widely used in, for example, a refrigerator for cooling a refrigerator that stores food or the like, an air conditioner that cools and heats a room, and the like.
　このような冷媒回路においては、圧縮機から吐出された冷媒には、その圧縮機内の潤滑に用いられた潤滑油が含まれている。潤滑油は、油分離器で回収され、圧縮機内に戻される。冷凍装置の運転状態に基づいて、圧縮機から流出する潤滑油の量を推定し、圧縮機内に貯留された潤滑油の油面が所定の高さより低下したと判断した場合には圧縮機内に潤滑油を戻す、という制御が知られている。例えば特許文献１には、冷媒の圧力、温度、モータ駆動電流の周波数等の条件に応じて、潤滑油を圧縮機に戻す油戻し管の電磁弁の制御が行われることが記載されている。このような制御により、圧縮機における潤滑油面の低下を抑え、圧縮機の信頼性を確保している。 In such a refrigerant circuit, the refrigerant discharged from the compressor contains lubricating oil used for lubrication in the compressor. The lubricating oil is recovered by the oil separator and returned to the compressor. Based on the operating condition of the refrigeration system, the amount of lubricating oil flowing out from the compressor is estimated, and when it is determined that the oil level of the lubricating oil stored in the compressor has dropped below a predetermined height, the lubricating oil is lubricated in the compressor. Control of returning oil is known. For example, Patent Document 1 describes that an electromagnetic valve of an oil return pipe that returns lubricating oil to a compressor is controlled according to conditions such as refrigerant pressure, temperature, and motor drive current frequency. By such control, the deterioration of the lubricating oil surface in the compressor is suppressed, and the reliability of the compressor is ensured.
特開２００３－２４０３６５号公報JP 2003-240365 A
　冷媒が十分に蒸発されない運転状態（例えば、デフロスト運転時や外気温が低い場合の暖房運転時）においては、いわゆる湿り運転が行われ易くなる。湿り運転では、冷媒が、その一部が液相のまま、圧縮機に吸入される。湿り運転が行われると、液冷媒が、圧縮機内に貯留されている潤滑油に溶解することにより、潤滑油中の冷媒濃度が大幅に増加することが知られている。潤滑油中の冷媒濃度が増加すると、潤滑油の粘度が低下し、摺動部での油膜生成能力の低下を招くことがある。そこで、例えば、潤滑油中の冷媒濃度が高くなると推定される運転条件（圧力、油温等）を設定しておき、設定された運転条件になった場合には過熱運転になるような運転モードに切換えるようにする方法が考えられる。 In an operation state where the refrigerant is not sufficiently evaporated (for example, during a defrost operation or a heating operation when the outside air temperature is low), a so-called wet operation is easily performed. In the wet operation, the refrigerant is sucked into the compressor while a part of the refrigerant remains in the liquid phase. It is known that when the wet operation is performed, the refrigerant concentration in the lubricating oil is greatly increased by dissolving the liquid refrigerant in the lubricating oil stored in the compressor. When the refrigerant concentration in the lubricating oil increases, the viscosity of the lubricating oil decreases, which may lead to a decrease in oil film generation capability at the sliding portion. Therefore, for example, operating conditions (pressure, oil temperature, etc.) presumed that the refrigerant concentration in the lubricating oil is increased are set, and an operation mode in which overheating operation is performed when the set operating conditions are reached. It is conceivable to switch to the above.
　しかしながら、このような方法では、冷媒濃度を直接測定しているわけでないので、実際の冷媒濃度に対応した適切な運転ができるとは限らない。特に、急激に冷媒濃度が上昇した場合には、冷媒濃度を十分に抑えることができず、圧縮機の信頼性が低下することがある。 However, in such a method, since the refrigerant concentration is not directly measured, it is not always possible to perform an appropriate operation corresponding to the actual refrigerant concentration. In particular, when the refrigerant concentration suddenly increases, the refrigerant concentration cannot be sufficiently suppressed, and the reliability of the compressor may be lowered.
　本発明は、潤滑油中の冷媒濃度を確実に抑えて、圧縮機の潤滑が十分に行えるようにすることを目的とする。 An object of the present invention is to reliably suppress the refrigerant concentration in the lubricating oil so that the compressor can be sufficiently lubricated.
　本開示の第１の態様は、圧縮機（10）を含む冷媒回路（1）を有し、上記冷媒回路（1）で冷媒を循環させて冷凍サイクルを行う冷凍装置であって、上記圧縮機（10）が吐出する冷媒から潤滑油を分離して貯留する油分離器（80）と、上記油分離器（80）に貯留された潤滑油を上記圧縮機（10）に戻す通常油戻し通路（86）と、上記油分離器（80）に貯留された潤滑油を上記圧縮機（10）に戻す緊急油戻し通路（88）と、上記圧縮機（10）の油溜まり（18）における潤滑油中の冷媒濃度に対応する信号を出力する冷媒濃度センサ（19）と、上記緊急油戻し通路（88）に設けられた開閉弁（89）と、上記冷媒濃度センサ（19）の出力信号に基づいて上記開閉弁（89）を制御するコントローラ（6）とを有する。上記油分離器（80）は、上記通常油戻し通路（86）に接続されている通常油取出口（81）と、上記通常油取出口（81）より下に形成され、上記緊急油戻し通路（88）に接続されている緊急油取出口（82）とを有する。上記コントローラ（6）は、上記油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きいことを上記冷媒濃度センサ（19）の出力信号が示す場合に、上記開閉弁（89）を開くように制御する。 1st aspect of this indication is a refrigerating apparatus which has a refrigerant circuit (1) containing a compressor (10), and circulates a refrigerant | coolant in the said refrigerant circuit (1), and performs a refrigerating cycle, Comprising: The said compressor An oil separator (80) that separates and stores lubricating oil from the refrigerant discharged from (10), and a normal oil return passage that returns the lubricating oil stored in the oil separator (80) to the compressor (10) (86), an emergency oil return passage (88) for returning the lubricating oil stored in the oil separator (80) to the compressor (10), and lubrication in the oil reservoir (18) of the compressor (10) The refrigerant concentration sensor (19) that outputs a signal corresponding to the refrigerant concentration in the oil, the on-off valve (89) provided in the emergency oil return passage (88), and the output signal of the refrigerant concentration sensor (19) And a controller (6) for controlling the on-off valve (89) based on the controller. The oil separator (80) is formed below the normal oil outlet (81) connected to the normal oil return passage (86), and the emergency oil return passage (81). And an emergency oil outlet (82) connected to (88). The controller (6) opens the on-off valve (89) when the output signal of the refrigerant concentration sensor (19) indicates that the refrigerant concentration in the lubricating oil in the oil reservoir (18) is greater than a predetermined value. To control.
　本開示の第１の態様の冷凍装置においては、圧縮機（10）が冷媒濃度センサ（19）を有している。このため、運転状態から潤滑油中の冷媒濃度を推定する場合より正確に、油溜まり（18）における潤滑油中の冷媒濃度を知ることができる。油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きい緊急時には、コントローラ（6）が冷媒濃度センサ（19）の出力に基づいて開閉弁（89）を開くので、油分離器（80）から圧縮機（10）へ潤滑油を即座に戻すことができる。圧縮機（10）へ潤滑油が戻ると、油溜まり（18）における潤滑油中の冷媒濃度が低下し、潤滑油の粘度が上昇する。つまり、この冷凍装置によると、潤滑油中の冷媒濃度を抑えることができ、潤滑油の粘度が低下し過ぎないようにすることができる。 In the refrigeration apparatus of the first aspect of the present disclosure, the compressor (10) has a refrigerant concentration sensor (19). For this reason, it is possible to know the refrigerant concentration in the lubricating oil in the oil sump (18) more accurately than when estimating the refrigerant concentration in the lubricating oil from the operating state. In an emergency where the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than a predetermined value, the controller (6) opens the on-off valve (89) based on the output of the refrigerant concentration sensor (19). ) Can be immediately returned to the compressor (10). When the lubricating oil returns to the compressor (10), the refrigerant concentration in the lubricating oil in the oil reservoir (18) decreases, and the viscosity of the lubricating oil increases. That is, according to this refrigeration apparatus, the refrigerant concentration in the lubricating oil can be suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing.
　油分離器（80）においては、緊急油戻し通路（88）に接続されている緊急油取出口（82）が、通常油戻し通路（86）に接続されている通常油取出口（81）より下に形成されている。このため、通常油取出口（81）からは取り出せないが緊急油取出口（82）からは取り出すことができる潤滑油を、緊急時用の潤滑油として確保することができる。したがって、緊急時には、この潤滑油を圧縮機に確実に戻すことができる。 In the oil separator (80), the emergency oil outlet (82) connected to the emergency oil return passage (88) is connected to the normal oil outlet (81) connected to the normal oil return passage (86). Formed below. For this reason, the lubricating oil that cannot be taken out from the normal oil outlet (81) but can be taken out from the emergency oil outlet (82) can be secured as the emergency lubricating oil. Therefore, in an emergency, this lubricating oil can be reliably returned to the compressor.
　本開示の第２の態様では、上記第１の態様において、上記圧縮機（10）は、冷媒が流入する吸入管（16）を有する。上記緊急油戻し通路（88）は、上記圧縮機（10）の上記吸入管（16）に接続されている。 In the second aspect of the present disclosure, in the first aspect, the compressor (10) includes a suction pipe (16) into which a refrigerant flows. The emergency oil return passage (88) is connected to the suction pipe (16) of the compressor (10).
　本開示の第２の態様によると、緊急油戻し通路（88）が圧縮機（10）の吸入管（16）に接続されているので、油戻しのための開口を圧縮機（10）に設ける必要がなく、潤滑油を容易に圧縮機（10）に戻すことができる。 According to the second aspect of the present disclosure, since the emergency oil return passage (88) is connected to the suction pipe (16) of the compressor (10), an opening for oil return is provided in the compressor (10). There is no need, and the lubricating oil can be easily returned to the compressor (10).
　本開示の第３の態様では、上記第２の態様において、上記圧縮機（10）は、上記圧縮機（10）の高圧空間に潤滑油を吸い込む吸込部（28）を有する。上記通常油戻し通路（86）は、上記吸込部（28）に接続されている。 In the third aspect of the present disclosure, in the second aspect, the compressor (10) includes a suction portion (28) that sucks lubricating oil into the high-pressure space of the compressor (10). The normal oil return passage (86) is connected to the suction part (28).
　本開示の第３の態様によると、圧縮機（10）は、高圧空間に潤滑油を吸い込む吸込部（28）を有する。このため、通常油戻し通路（86）を流れる潤滑油を高圧空間に直接戻すことができる。潤滑油や冷媒が高圧空間に戻っても、圧縮機（10）の性能にはほとんど影響を及ぼさないので、通常油戻し通路（86）の潤滑油の流量を調節する機構を有する必要がない。したがって、低コスト化を図ることができる。 According to the third aspect of the present disclosure, the compressor (10) has a suction part (28) that sucks lubricating oil into the high-pressure space. For this reason, the lubricating oil flowing through the normal oil return passage (86) can be directly returned to the high-pressure space. Even if the lubricating oil or refrigerant returns to the high-pressure space, the performance of the compressor (10) is hardly affected, and therefore it is not necessary to have a mechanism for adjusting the flow rate of the lubricating oil in the normal oil return passage (86). Therefore, cost reduction can be achieved.
　本開示の第４の態様では、上記第２の態様において、上記冷凍装置は、上記通常油戻し通路（86）に設けられた制御機構（87）を更に有する。上記通常油戻し通路（86）は、上記圧縮機（10）の上記吸入管（16）に接続されており、上記コントローラ（6）は、上記冷媒濃度センサ（19）の出力信号に基づいて上記通常油戻し通路(86)の潤滑油流量を制御する。 In the fourth aspect of the present disclosure, in the second aspect, the refrigeration apparatus further includes a control mechanism (87) provided in the normal oil return passage (86). The normal oil return passage (86) is connected to the suction pipe (16) of the compressor (10), and the controller (6) is based on an output signal of the refrigerant concentration sensor (19). The flow rate of the lubricating oil in the normal oil return passage (86) is controlled.
　本開示の第４の態様によると、コントローラ（6）は、上記冷媒濃度センサ（19）の出力信号に基づいて、通常油戻し通路（86）の潤滑油流量を制御するので、油分離器（80）から圧縮機（10）へ通常油戻し通路（86）を用いて潤滑油を戻す制御の精度が高くなる。 According to the fourth aspect of the present disclosure, the controller (6) controls the lubricating oil flow rate in the normal oil return passage (86) based on the output signal of the refrigerant concentration sensor (19). The accuracy of control for returning the lubricating oil from 80) to the compressor (10) using the normal oil return passage (86) is increased.
　本開示の第５の態様では、上記第１の態様において、上記圧縮機（10）は、上記圧縮機（10）の高圧空間に連通する油戻し口（14）を有し、上記緊急油戻し通路（88）は、上記油戻し口（14）に接続されており、上記油分離器（80）の上記緊急油取出口（82）は、上記油戻し口（14）より高い位置に配置されている。 In a fifth aspect of the present disclosure, in the first aspect, the compressor (10) has an oil return port (14) communicating with a high-pressure space of the compressor (10), and the emergency oil return The passage (88) is connected to the oil return port (14), and the emergency oil outlet (82) of the oil separator (80) is disposed at a position higher than the oil return port (14). ing.
　本開示の第５の態様によると、潤滑油が、緊急油戻し通路（88）を通って、高圧の油分離器（80）から圧縮機（10）内の高圧空間に重力によって戻される。このため、油溜まり（18）の潤滑油の量が早く回復し、油溜まり（18）における潤滑油中の冷媒濃度を素早く低下させることができる。また、潤滑油が吸入側の低圧の空間に戻される場合に生じるような効率の低下が生じない。 According to the fifth aspect of the present disclosure, the lubricating oil is returned to the high pressure space in the compressor (10) from the high pressure oil separator (80) through the emergency oil return passage (88) by gravity. For this reason, the amount of lubricating oil in the oil reservoir (18) can be recovered quickly, and the refrigerant concentration in the lubricating oil in the oil reservoir (18) can be quickly reduced. Further, there is no reduction in efficiency that occurs when the lubricating oil is returned to the low-pressure space on the suction side.
　本開示の第６の態様では、上記第５の態様において、上記圧縮機（10）は、上記圧縮機（10）の高圧空間に潤滑油を吸い込む吸込部（28）を有し、上記通常油戻し通路（86）は、上記吸込部（28）に接続されている。 In a sixth aspect of the present disclosure, in the fifth aspect, the compressor (10) includes a suction portion (28) that sucks lubricating oil into a high-pressure space of the compressor (10), and the normal oil The return passage (86) is connected to the suction part (28).
　本開示の第６の態様によると、圧縮機（10）は、高圧空間に潤滑油を吸い込む吸込部（28）を有する。このため、通常油戻し通路（86）を流れる潤滑油を高圧空間に直接戻すことができる。潤滑油や冷媒が高圧空間に戻っても、圧縮機（10）の性能にはほとんど影響を及ぼさないので、通常油戻し通路（86）の潤滑油の流量を調節する機構を有する必要がなく、低コスト化を図ることができる。 According to the sixth aspect of the present disclosure, the compressor (10) has the suction portion (28) that sucks the lubricating oil into the high-pressure space. For this reason, the lubricating oil flowing through the normal oil return passage (86) can be directly returned to the high-pressure space. Even if the lubricating oil or refrigerant returns to the high-pressure space, the performance of the compressor (10) is hardly affected. Therefore, it is not necessary to have a mechanism for adjusting the flow rate of the lubricating oil in the normal oil return passage (86). Cost reduction can be achieved.
　本開示の第７の態様では、上記第１の態様において、上記冷媒濃度センサ（19）は、静電容量式のセンサである。 In the seventh aspect of the present disclosure, in the first aspect, the refrigerant concentration sensor (19) is a capacitance type sensor.
　本開示の第７の態様によると、冷媒濃度センサ（19）は、静電容量式のセンサであるので、圧縮機（10）の油溜まり（18）における潤滑油中の冷媒濃度に対応する信号を容易に得ることができる。 According to the seventh aspect of the present disclosure, since the refrigerant concentration sensor (19) is a capacitance type sensor, a signal corresponding to the refrigerant concentration in the lubricating oil in the oil reservoir (18) of the compressor (10). Can be easily obtained.
　本開示によれば、潤滑油中の冷媒濃度を確実に抑えることができ、潤滑油の粘度が低下し過ぎないようにすることができる。したがって、圧縮機の潤滑をより確実に行うことができ、圧縮機及びこれを有する冷凍装置の信頼性を向上させることができる。 According to the present disclosure, the refrigerant concentration in the lubricating oil can be reliably suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing. Therefore, the compressor can be more reliably lubricated, and the reliability of the compressor and the refrigeration apparatus having the compressor can be improved.
図１は、本発明の実施形態に係る冷凍装置の冷媒回路の構成例を示す冷媒回路図である。FIG. 1 is a refrigerant circuit diagram illustrating a configuration example of a refrigerant circuit of a refrigeration apparatus according to an embodiment of the present invention. 図２は、図１の圧縮機及び油分離器に関する配管系統図である。FIG. 2 is a piping system diagram related to the compressor and oil separator of FIG. 図３は、図２の弁の制御に関するブロック図である。FIG. 3 is a block diagram relating to the control of the valve of FIG. 図４は、本実施形態の変形例１に係る冷凍装置の圧縮機及び油分離器に関する配管系統図である。FIG. 4 is a piping system diagram regarding the compressor and the oil separator of the refrigeration apparatus according to Modification 1 of the present embodiment. 図５は、エジェクタの構造例を示す縦断面図である。FIG. 5 is a longitudinal sectional view showing an example of the structure of the ejector. 図６は、本実施形態の変形例２に係る冷凍装置の圧縮機及び油分離器に関する配管系統図である。FIG. 6 is a piping system diagram related to the compressor and the oil separator of the refrigeration apparatus according to the second modification of the present embodiment.
　以下、本発明の実施の形態について、図面を参照しながら説明する。図面において同じ参照番号で示された構成要素は、同一の又は類似の構成要素である。本明細書において、「流量」は単位時間当たりの量を示す。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components shown with the same reference numbers in the drawings are identical or similar components. In this specification, “flow rate” indicates an amount per unit time.
　図１は、本発明の実施形態に係る冷凍装置（100）の冷媒回路（1）の構成例を示す冷媒回路図である。冷凍装置（100）は、冷媒回路（1）を有し、冷媒回路（1）で冷媒を循環させて冷凍サイクルを行う。図１の冷媒回路（1）は、蒸気圧縮式冷凍サイクルを行う冷媒回路であって、圧縮機（10）と、油分離器（80）と、凝縮器（2）と、膨張弁（3）と、蒸発器（4）とを有している。冷媒回路（1）は、圧縮機（10）、油分離器（80）、凝縮器（2）、膨張弁（3）、及び蒸発器（4）がこの順に冷媒配管で接続された閉回路である。冷凍装置（100）は、空気調和装置等にも用いられる。 FIG. 1 is a refrigerant circuit diagram illustrating a configuration example of a refrigerant circuit (1) of a refrigeration apparatus (100) according to an embodiment of the present invention. The refrigeration apparatus (100) has a refrigerant circuit (1) and performs a refrigeration cycle by circulating refrigerant in the refrigerant circuit (1). The refrigerant circuit (1) in FIG. 1 is a refrigerant circuit that performs a vapor compression refrigeration cycle, and includes a compressor (10), an oil separator (80), a condenser (2), and an expansion valve (3). And an evaporator (4). The refrigerant circuit (1) is a closed circuit in which the compressor (10), oil separator (80), condenser (2), expansion valve (3), and evaporator (4) are connected in this order by refrigerant piping. is there. The refrigeration apparatus (100) is also used for an air conditioner or the like.
　図２は、図１の圧縮機（10）及び油分離器（80）に関する配管系統図である。圧縮機（10）は、回転式圧縮機であって、例えば図２のようなスクロール圧縮機である。図２の圧縮機（10）は、ケーシング（15）と、圧縮機構（20）と、電動機（50）と、駆動軸（60）とを有している。ケーシング（15）の内部には、圧縮機構（20）、電動機（50）、及び駆動軸（60）等が収容されている。駆動軸（60）は、上下方向へ延びる姿勢で配置され、圧縮機構（20）と電動機（50）を連結している。 FIG. 2 is a piping system diagram related to the compressor (10) and the oil separator (80) of FIG. The compressor (10) is a rotary compressor, for example, a scroll compressor as shown in FIG. The compressor (10) of FIG. 2 has a casing (15), a compression mechanism (20), an electric motor (50), and a drive shaft (60). The casing (15) accommodates a compression mechanism (20), an electric motor (50), a drive shaft (60), and the like. The drive shaft (60) is arranged in a posture extending in the vertical direction, and connects the compression mechanism (20) and the electric motor (50).
　ケーシング（15）には、吸入管（16）と吐出管（17）が設けられている。吸入管（16）は、ケーシング（15）の頂部を貫通しており、ケーシング（15）内における圧縮機構（20）の上の上部空間（11）に開口している。吸入管（16）は蒸発器（4）に接続され、吸入管（16）には蒸発器（4）からの冷媒が流入する。吐出管（17）は、ケーシング（15）の側面を貫通しており、ケーシング（15）内における圧縮機構（20）の下の下部空間（12）に開口している。圧縮機構（20）は、低圧の上部空間（11）から吸い込んだ冷媒を圧縮して高圧の下部空間（12）へ吐出する。吐出管（17）は凝縮器（2）に接続されている。ケーシング（15）の底部には、潤滑油（例えば冷凍機油）が貯留されている。つまり、ケーシング（15）内には、油溜まり（18）が形成されている。 The casing (15) is provided with a suction pipe (16) and a discharge pipe (17). The suction pipe (16) passes through the top of the casing (15) and opens into the upper space (11) above the compression mechanism (20) in the casing (15). The suction pipe (16) is connected to the evaporator (4), and the refrigerant from the evaporator (4) flows into the suction pipe (16). The discharge pipe (17) penetrates the side surface of the casing (15) and opens into the lower space (12) below the compression mechanism (20) in the casing (15). The compression mechanism (20) compresses the refrigerant sucked from the low pressure upper space (11) and discharges it to the high pressure lower space (12). The discharge pipe (17) is connected to the condenser (2). Lubricating oil (for example, refrigerating machine oil) is stored at the bottom of the casing (15). That is, an oil sump (18) is formed in the casing (15).
　駆動軸（60）の内部には、その軸方向へ延びる給油通路が形成されている。この給油通路の下端には、給油ポンプが取り付けられている。給油ポンプは、例えばトロコイドポンプであるが、これには限られない。駆動軸（60）が回転すると、給油ポンプは油溜まり（18）から潤滑油を吸い込んで、給油通路に供給する。潤滑油は、圧縮機構（20）や、駆動軸（60）の軸受へ供給され、これらの潤滑に利用される。潤滑に利用された後、その潤滑油のほとんどは油溜まり（18）に戻る。 The oil supply passage extending in the axial direction is formed inside the drive shaft (60). An oil supply pump is attached to the lower end of the oil supply passage. The oil supply pump is, for example, a trochoid pump, but is not limited thereto. When the drive shaft (60) rotates, the oil supply pump draws lubricating oil from the oil reservoir (18) and supplies it to the oil supply passage. Lubricating oil is supplied to the compression mechanism (20) and the bearing of the drive shaft (60) and used for lubrication thereof. After being used for lubrication, most of the lubricant returns to the sump (18).
　圧縮機（10）は、ケーシング（15）内に冷媒濃度センサ（19）を有している。冷媒濃度センサ（19）は、例えば、ケーシング（15）の底部に、圧縮機（10）の油溜まり（18）の潤滑油に浸されるように配置されている。冷媒濃度センサ（19）は、潤滑油面の高さの変化の影響を受けにくいように、冷媒濃度センサ（19）の高さが低くなるような向きに、低い位置に配置されるのが望ましい。冷媒濃度センサ（19）は、ケーシング（15）の底に接していてもよいし、接していなくてもよい。冷媒濃度センサ（19）は、油溜まり（18）における潤滑油中の冷媒濃度に対応する信号を出力する。冷媒濃度センサ（19）は、例えば静電容量式のセンサであって、２つの電極間の静電容量に対応する信号を出力する。潤滑油中の冷媒濃度に応じて電極間の静電容量が変化するので、冷媒濃度を測定することができる。 The compressor (10) has a refrigerant concentration sensor (19) in the casing (15). For example, the refrigerant concentration sensor (19) is disposed at the bottom of the casing (15) so as to be immersed in the lubricating oil in the oil reservoir (18) of the compressor (10). It is desirable that the refrigerant concentration sensor (19) be arranged at a low position in such a direction that the refrigerant concentration sensor (19) is lowered so as not to be affected by the change in the height of the lubricating oil surface. . The refrigerant concentration sensor (19) may be in contact with the bottom of the casing (15) or may not be in contact therewith. The refrigerant concentration sensor (19) outputs a signal corresponding to the refrigerant concentration in the lubricating oil in the oil reservoir (18). The refrigerant concentration sensor (19) is, for example, a capacitance type sensor, and outputs a signal corresponding to the capacitance between the two electrodes. Since the capacitance between the electrodes changes according to the refrigerant concentration in the lubricating oil, the refrigerant concentration can be measured.
　圧縮機構（20）で圧縮された冷媒は、吐出管（17）から吐出され、油分離器（80）に供給される。吐出された冷媒には潤滑油が混ざっている。油分離器（80）は、この冷媒から潤滑油を分離して貯留し、冷媒を凝縮器（2）に吐出する。貯留された潤滑油は、油分離器（80）内に油溜まり（85）を形成する。 The refrigerant compressed by the compression mechanism (20) is discharged from the discharge pipe (17) and supplied to the oil separator (80). Lubricating oil is mixed in the discharged refrigerant. The oil separator (80) separates and stores the lubricating oil from the refrigerant, and discharges the refrigerant to the condenser (2). The stored lubricating oil forms an oil reservoir (85) in the oil separator (80).
　冷凍装置（100）は、図２のように、通常油戻し通路（86）と、制御機構（87）と、緊急油戻し通路（88）と、開閉弁（89）とを有している。油分離器（80）は、通常油取出口（81）と、緊急油取出口（82）とを有している。通常油取出口（81）は、油分離器（80）の側面に貫通するように形成されている。緊急油取出口（82）は、通常油取出口（81）より下に、例えば油分離器（80）の底部に貫通するように形成されている。 The refrigeration apparatus (100) has a normal oil return passage (86), a control mechanism (87), an emergency oil return passage (88), and an on-off valve (89) as shown in FIG. The oil separator (80) has a normal oil outlet (81) and an emergency oil outlet (82). Usually, the oil outlet (81) is formed so as to penetrate the side surface of the oil separator (80). The emergency oil outlet (82) is formed below the normal oil outlet (81), for example, so as to penetrate the bottom of the oil separator (80).
　通常油戻し通路（86）及び緊急油戻し通路（88）は、いずれも、油分離器（80）に貯留された潤滑油を圧縮機（10）に戻す。具体的には、通常油取出口（81）は、通常油戻し通路（86）の一端に接続されている。緊急油取出口（82）は、緊急油戻し通路（88）の一端に接続されている。通常油戻し通路（86）の他端は、例えば蒸発器（4）と吸入管（16）とを接続する配管を介して、吸入管（16）に接続されている。緊急油戻し通路（88）の他端も、例えば蒸発器（4）と吸入管（16）とを接続する配管を介して、吸入管（16）に接続されている。 Both the normal oil return passage (86) and the emergency oil return passage (88) return the lubricating oil stored in the oil separator (80) to the compressor (10). Specifically, the normal oil outlet (81) is connected to one end of the normal oil return passage (86). The emergency oil outlet (82) is connected to one end of the emergency oil return passage (88). The other end of the normal oil return passage (86) is connected to the suction pipe (16), for example, via a pipe connecting the evaporator (4) and the suction pipe (16). The other end of the emergency oil return passageway (88) is also connected to the suction pipe (16) via, for example, a pipe connecting the evaporator (4) and the suction pipe (16).
　制御機構（87）は、通常油戻し通路（86）に設けられており、開閉弁（89）は、緊急油戻し通路（88）に設けられている。制御機構(87)としては、例えば電動弁、又は電磁弁（開閉弁）が用いられる。電動弁又は電磁弁のみ、これらの弁のいずれかとキャピラリとの組み合わせ、又は、キャピラリのみによって、通常油戻し通路(86)の潤滑油流量が制御される。 The control mechanism (87) is normally provided in the oil return passage (86), and the on-off valve (89) is provided in the emergency oil return passage (88). As the control mechanism (87), for example, an electric valve or a solenoid valve (open / close valve) is used. The lubricating oil flow rate of the normal oil return passageway (86) is controlled only by the motor-operated valve or the electromagnetic valve, the combination of any of these valves and the capillary, or only the capillary.
　図３は、図２の弁の制御に関するブロック図である。冷凍装置（100）は、コントローラ（6）を有する。コントローラ（6）は、冷媒濃度センサ（19）の出力信号に基づいて制御機構（87）及び開閉弁（89）を制御する。より具体的には、コントローラ（6）は、例えば、圧縮機（10）の油溜まり（18）の潤滑油中の冷媒濃度が大きいほど制御機構（87）としての電動弁の開度を大きくしたり、潤滑油中の冷媒濃度が基準値より大きい場合に制御機構（87）としての電磁弁を開にしたりして、通常油戻し通路(86)の潤滑油流量を大きくする。また、コントローラ（6）は、油溜まり（18）の潤滑油中の冷媒濃度が所定値より大きいことを冷媒濃度センサ（19）の出力信号が示す場合に、開閉弁（89）を開くように制御する。この所定値は基準値より大きい。油溜まり（18）の潤滑油中の冷媒濃度がこの所定値又はこれより十分に低い値に達すると、コントローラ（6）は開閉弁（89）を閉じる。 FIG. 3 is a block diagram relating to the control of the valve of FIG. The refrigeration apparatus (100) has a controller (6). The controller (6) controls the control mechanism (87) and the on-off valve (89) based on the output signal of the refrigerant concentration sensor (19). More specifically, for example, the controller (6) increases the opening of the motor-operated valve as the control mechanism (87) as the refrigerant concentration in the lubricating oil in the oil sump (18) of the compressor (10) increases. When the refrigerant concentration in the lubricating oil is larger than the reference value, the solenoid valve as the control mechanism (87) is opened to increase the flow rate of the lubricating oil in the normal oil return passage (86). Further, the controller (6) opens the on-off valve (89) when the output signal of the refrigerant concentration sensor (19) indicates that the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than a predetermined value. Control. This predetermined value is larger than the reference value. When the refrigerant concentration in the lubricating oil in the oil reservoir (18) reaches the predetermined value or a value sufficiently lower than the predetermined value, the controller (6) closes the on-off valve (89).
　　－運転動作－
　冷凍装置（100）の動作について説明する。圧縮機（10）では、電動機（50）によって圧縮機構（20）が回転駆動される。圧縮機構（20）は、吸入管（16）から吸い込んだ冷媒を圧縮してケーシング（15）内へ吐出する。圧縮機（10）の運転中には、ケーシング（15）内の油溜まり（18）から圧縮機構（20）へ潤滑油が供給される。圧縮機構（20）へ供給された潤滑油は圧縮機構（20）の潤滑に利用されるが、その一部は圧縮後の冷媒と共にケーシング（15）の内部空間へ吐出される。圧縮機構（20）から冷媒と共に吐出された潤滑油は、電動機（50）の上下空間内、及び、電動機（50）の回転子と固定子の間に形成された隙間や、固定子とケーシング（15）の間に形成された隙間などを通過する間にその一部が冷媒から分離される。ケーシング（15）内で冷媒から分離された潤滑油は、油溜まり（18）へと流れ落ちてゆく。一方、冷媒から分離されなかった潤滑油は、冷媒と共に吐出管（17）を通って圧縮機（10）の外部へ流出してゆく。 -Driving operation-
The operation of the refrigeration apparatus (100) will be described. In the compressor (10), the compression mechanism (20) is rotationally driven by the electric motor (50). The compression mechanism (20) compresses the refrigerant sucked from the suction pipe (16) and discharges it into the casing (15). During operation of the compressor (10), lubricating oil is supplied from the oil sump (18) in the casing (15) to the compression mechanism (20). Although the lubricating oil supplied to the compression mechanism (20) is used for lubrication of the compression mechanism (20), a part of the lubricating oil is discharged into the internal space of the casing (15) together with the compressed refrigerant. Lubricating oil discharged together with the refrigerant from the compression mechanism (20) is a gap formed in the upper and lower spaces of the electric motor (50) and between the rotor and the stator of the electric motor (50), and the stator and casing ( Part of it is separated from the refrigerant while passing through the gap formed during 15). The lubricating oil separated from the refrigerant in the casing (15) flows down to the oil reservoir (18). On the other hand, the lubricating oil that has not been separated from the refrigerant flows out of the compressor (10) through the discharge pipe (17) together with the refrigerant.
　油分離器（80）は、冷媒から潤滑油を分離して貯留し、冷媒を凝縮器（2）に吐出する。冷媒は、凝縮器（2）で放熱し、膨張弁（3）を通って蒸発器（4）へ流入する。蒸発器（4）では、流入した冷媒が周囲の空気から吸熱して蒸発し、空気が冷却される。蒸発器（4）から出た低圧冷媒は、圧縮機（10）の吸入管（16）へ流入する。 The oil separator (80) separates and stores the lubricating oil from the refrigerant, and discharges the refrigerant to the condenser (2). The refrigerant dissipates heat in the condenser (2) and flows into the evaporator (4) through the expansion valve (3). In the evaporator (4), the refrigerant flowing in absorbs heat from the surrounding air and evaporates to cool the air. The low-pressure refrigerant discharged from the evaporator (4) flows into the suction pipe (16) of the compressor (10).
　ケーシング（15）内に液相の冷媒が流入すると、それに伴って油溜まり（18）における潤滑油中の冷媒濃度が上昇する。コントローラ（6）は、冷媒濃度センサ（19）の出力信号に基づいて、例えば、圧縮機（10）の油溜まり（18）の潤滑油中の冷媒濃度が大きいほど制御機構（87）としての電動弁の開度を大きくしたり、潤滑油中の冷媒濃度が基準値より大きい場合に制御機構（87）としての電磁弁を開にする。油分離器（80）には、圧縮機（10）から高圧の冷媒が流入し、油分離器（80）の内部は高圧になっている。圧縮機（10）の吸入管（16）は、圧縮機（10）の低圧の上部空間（11）に連通している。したがって、制御機構（87）としての電動弁や電磁弁が開くと、油分離器（80）の油溜まり（85）の潤滑油は、通常油戻し通路（86）を通って圧縮機（10）の吸入管（16）へ流入する。 When the liquid refrigerant flows into the casing (15), the refrigerant concentration in the lubricating oil in the oil sump (18) increases accordingly. Based on the output signal of the refrigerant concentration sensor (19), for example, the controller (6) operates as an electric motor as the control mechanism (87) as the refrigerant concentration in the lubricating oil in the oil reservoir (18) of the compressor (10) increases. When the opening degree of the valve is increased or the refrigerant concentration in the lubricating oil is larger than the reference value, the electromagnetic valve as the control mechanism (87) is opened. High pressure refrigerant flows from the compressor (10) into the oil separator (80), and the inside of the oil separator (80) is at high pressure. The suction pipe (16) of the compressor (10) communicates with the low pressure upper space (11) of the compressor (10). Therefore, when the motor-operated valve or solenoid valve as the control mechanism (87) is opened, the lubricating oil in the oil reservoir (85) of the oil separator (80) passes through the normal oil return passage (86) and the compressor (10). Into the suction pipe (16).
　油溜まり（18）の潤滑油中の冷媒濃度が所定値より大きい時には、潤滑油の粘度が低下しているので、油分離器（80）の潤滑油を圧縮機（10）に緊急に戻す必要がある。このような時には、コントローラ（6）は、冷媒濃度センサ（19）の出力信号に基づいて、開閉弁（89）を開く。すると、油分離器（80）の油溜まり（85）の潤滑油は、緊急油戻し通路（88）を通って圧縮機（10）の吸入管（16）へ流入する。すると、圧縮機（10）の油溜まり（18）における潤滑油の割合が増加し、冷媒濃度が低下して、潤滑油の粘度が上昇する。 When the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than the specified value, the viscosity of the lubricating oil has dropped, so the oil in the oil separator (80) must be returned to the compressor (10) urgently. There is. At such time, the controller (6) opens the on-off valve (89) based on the output signal of the refrigerant concentration sensor (19). Then, the lubricating oil in the oil reservoir (85) of the oil separator (80) flows into the suction pipe (16) of the compressor (10) through the emergency oil return passage (88). Then, the ratio of the lubricating oil in the oil sump (18) of the compressor (10) increases, the refrigerant concentration decreases, and the viscosity of the lubricating oil increases.
　　－効果－
　本実施形態では、圧縮機（10）が冷媒濃度センサ（19）を有している。このため、より正確に、油溜まり（18）における潤滑油中の冷媒濃度を知ることができる。油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きい緊急時には、コントローラ（6）が冷媒濃度センサ（19）の出力に基づいて開閉弁（89）を開くので、油分離器（80）から圧縮機（10）へ潤滑油を即座に戻すことができる。圧縮機（10）へ潤滑油が戻ると、油溜まり（18）における潤滑油中の冷媒濃度が低下し、潤滑油の粘度が上昇する。つまり、本実施形態の冷凍装置によると、潤滑油中の冷媒濃度を確実に抑えることができ、潤滑油の粘度が低下し過ぎないようにすることができる。 -effect-
In the present embodiment, the compressor (10) has a refrigerant concentration sensor (19). For this reason, the refrigerant | coolant density | concentration in the lubricating oil in an oil sump (18) can be known more correctly. In an emergency where the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than a predetermined value, the controller (6) opens the on-off valve (89) based on the output of the refrigerant concentration sensor (19). ) Can be immediately returned to the compressor (10). When the lubricating oil returns to the compressor (10), the refrigerant concentration in the lubricating oil in the oil reservoir (18) decreases, and the viscosity of the lubricating oil increases. That is, according to the refrigeration apparatus of this embodiment, the refrigerant concentration in the lubricating oil can be reliably suppressed, and the viscosity of the lubricating oil can be prevented from excessively decreasing.
　また、コントローラ（6）が、冷媒濃度センサ（19）の出力に基づいて制御機構（87）としての電動弁や電磁弁を制御する。このため、油分離器（80）から圧縮機（10）へ通常油戻し通路（86）を用いて潤滑油を戻す制御の精度が高くなる。 Also, the controller (6) controls the motor operated valve and electromagnetic valve as the control mechanism (87) based on the output of the refrigerant concentration sensor (19). For this reason, the accuracy of control for returning the lubricating oil from the oil separator (80) to the compressor (10) using the normal oil return passage (86) is increased.
　油分離器（80）においては、緊急油戻し通路（88）に接続されている緊急油取出口（82）が、通常油戻し通路（86）に接続されている通常油取出口（81）より下に形成されている。このため、通常油取出口（81）からは取り出せないが緊急油取出口（82）からは取り出すことができる潤滑油を、緊急時用の潤滑油として確保することができ、緊急時には、この潤滑油を圧縮機（10）に確実に戻すことができる。 In the oil separator (80), the emergency oil outlet (82) connected to the emergency oil return passage (88) is connected to the normal oil outlet (81) connected to the normal oil return passage (86). Formed below. For this reason, lubricating oil that cannot be taken out from the normal oil outlet (81) but can be taken out from the emergency oil outlet (82) can be secured as an emergency lubricating oil. The oil can be reliably returned to the compressor (10).
　このように、本実施形態によると、潤滑油の粘度が低下し過ぎないようにすることができる。その結果、圧縮機（10）の潤滑をより確実に行うことができ、圧縮機（10）及びこれを有する冷凍装置（100）の信頼性を向上させることができる。 Thus, according to the present embodiment, the viscosity of the lubricating oil can be prevented from excessively decreasing. As a result, the compressor (10) can be more reliably lubricated, and the reliability of the compressor (10) and the refrigeration apparatus (100) having the compressor (10) can be improved.
　変形例１
　図４は、本実施形態の変形例１に係る冷凍装置(100)の圧縮機（10）及び油分離器（80）に関する配管系統図である。圧縮機（10）は、潤滑油を吸い込む油吸込口（13）を有する。図４の装置においては、通常油戻し通路（86）が、吸入管（16）ではなく油吸込口（13）に接続され、制御機構（87）が省略されている。また、圧縮機（10）は、圧縮機（10）の高圧空間に潤滑油を吸い込む吸込部としてのエジェクタ（28）を有している。変形例１に係る冷凍装置(100)は、その他の点は、図１及び図２を参照して説明した実施形態の冷凍装置（100）とほぼ同様に構成されている。 Modification 1
FIG. 4 is a piping system diagram related to the compressor (10) and the oil separator (80) of the refrigeration apparatus (100) according to the first modification of the present embodiment. The compressor (10) has an oil suction port (13) for sucking lubricating oil. In the apparatus of FIG. 4, the normal oil return passageway (86) is connected to the oil suction port (13) instead of the suction pipe (16), and the control mechanism (87) is omitted. Moreover, the compressor (10) has an ejector (28) as a suction portion that sucks lubricating oil into the high-pressure space of the compressor (10). The refrigeration apparatus (100) according to the first modification is configured in substantially the same manner as the refrigeration apparatus (100) of the embodiment described with reference to FIGS.
　図５は、エジェクタ（28）の構造例を示す縦断面図である。エジェクタ（28）は、例えば圧縮機（10）内のハウジング（25）の一部を構成している。通常油戻し通路（86）は、油吸込口（13）を介してエジェクタ（28）の接続部（28C）に接続されており、通常油戻し通路（86）は、接続部（28C）の連通路（28D）に連通している。 FIG. 5 is a longitudinal sectional view showing an example of the structure of the ejector (28). The ejector (28) constitutes a part of the housing (25) in the compressor (10), for example. The normal oil return passage (86) is connected to the connection (28C) of the ejector (28) via the oil suction port (13), and the normal oil return passage (86) is connected to the connection (28C). It communicates with the passage (28D).
　図５に示すように、エジェクタ（28）では、圧縮機構（20）から吐出された高圧の冷媒が内部流路（28E）に流入する。内部流路（28E）に流入した冷媒は、ノズル部（28A）において圧力エネルギの一部が速度エネルギに変換され、圧力が低下すると共に加速されてノズル部（28A）から噴射される。このようなノズル部（28A）における冷媒の圧力低下によって、通常油戻し通路（86）の潤滑油が接続部（28C）の連通路（28D）を介して内部流路（28E）に吸引される。つまり、通常油戻し通路（86）の潤滑油が、ノズル部（28A）から噴射される冷媒に吸引されて合流する。合流した冷媒と潤滑油は、その速度エネルギの一部が拡径部（28B）において圧力エネルギに変換され、減速すると共に圧力が上昇して、エジェクタ（28）から下部空間（12）に流出する。 As shown in FIG. 5, in the ejector (28), the high-pressure refrigerant discharged from the compression mechanism (20) flows into the internal flow path (28E). The refrigerant that has flowed into the internal flow path (28E) is partly converted into velocity energy in the nozzle portion (28A), is accelerated as the pressure decreases, and is jetted from the nozzle portion (28A). Due to the pressure drop of the refrigerant in the nozzle portion (28A), the lubricating oil in the normal oil return passage (86) is sucked into the internal flow path (28E) through the communication passage (28D) of the connection portion (28C). . That is, the lubricating oil in the normal oil return passage (86) is sucked and joined by the refrigerant injected from the nozzle portion (28A). Part of the velocity energy of the merged refrigerant and lubricating oil is converted to pressure energy in the enlarged diameter portion (28B), decelerates and the pressure rises, and flows out from the ejector (28) to the lower space (12). .
　油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きい緊急時には、図２の冷凍装置（100）と同様に、コントローラ（6）が冷媒濃度センサ（19）の出力に基づいて開閉弁（89）を開く。このため、油分離器（80）から圧縮機（10）へ潤滑油を即座に戻すことができ、圧縮機（10）及び冷凍装置（100）の信頼性を向上させることができる。 In an emergency when the refrigerant concentration in the lubricating oil in the oil sump (18) is greater than a predetermined value, the controller (6) opens and closes the open / close valve based on the output of the refrigerant concentration sensor (19), as in the refrigeration apparatus (100) of FIG. Open (89). For this reason, lubricating oil can be immediately returned from the oil separator (80) to the compressor (10), and the reliability of the compressor (10) and the refrigeration apparatus (100) can be improved.
　なお、エジェクタ（28）に代えてポンプ等を吸込部として用いて、通常油戻し通路（86）の潤滑油を圧縮機（10）の下部空間（12）に戻すようにしてもよい。 Note that the lubricating oil in the normal oil return passage (86) may be returned to the lower space (12) of the compressor (10) by using a pump or the like as a suction portion instead of the ejector (28).
　このように、図４の変形例１によると、通常油戻し通路（86）を流れる潤滑油が圧縮機（10）内の高圧の下部空間（12）に直接戻される。多量の潤滑油や冷媒が下部空間（12）に戻っても、圧縮機（10）の性能にはほとんど影響を及ぼさないので、通常油戻し通路（86）の潤滑油の流量を調節する制御機構（87）が不要となる。また、エジェクタ（28）を設ける場合には、ポンプ等の昇圧手段を設ける必要がない。したがって、低コストで、油分離器（80）の潤滑油を圧縮機（10）に適切に戻すことができる。更に、潤滑油が、高圧の油分離器（80）から圧縮機（10）内の高圧の下部空間（12）に戻されるので、吸入側の過熱度に影響を与えず、容積効率の低下が生じない。このため、高効率運転と信頼性の向上とを両立させることができる。 Thus, according to the first modification of FIG. 4, the lubricating oil flowing through the normal oil return passage (86) is directly returned to the high pressure lower space (12) in the compressor (10). Even if a large amount of lubricating oil or refrigerant returns to the lower space (12), it hardly affects the performance of the compressor (10), so a control mechanism that adjusts the lubricating oil flow rate in the normal oil return passage (86) (87) becomes unnecessary. Further, when the ejector (28) is provided, it is not necessary to provide a boosting means such as a pump. Therefore, the lubricating oil in the oil separator (80) can be appropriately returned to the compressor (10) at low cost. Furthermore, since the lubricating oil is returned from the high-pressure oil separator (80) to the high-pressure lower space (12) in the compressor (10), the volumetric efficiency is reduced without affecting the degree of superheat on the suction side. Does not occur. For this reason, it is possible to achieve both high-efficiency operation and improved reliability.
　変形例２
　図６は、本実施形態の変形例２に係る冷凍装置(100)の圧縮機（10）及び油分離器（80）に関する配管系統図である。圧縮機（10）は、圧縮機（10）の高圧空間である下部空間（12）に連通する油戻し口（14）を有する。図６の装置においては、緊急油戻し通路（88）が、吸入管（16）ではなく、油戻し口（14）に接続されている。油分離器（80）の緊急油取出口（82）は、油戻し口（14）より高い位置に配置されている。変形例２に係る冷凍装置(100)は、その他の点は、図４を参照して説明した変形例１の冷凍装置(100)とほぼ同様に構成されている。 Modification 2
FIG. 6 is a piping diagram related to the compressor (10) and the oil separator (80) of the refrigeration apparatus (100) according to the second modification of the present embodiment. The compressor (10) has an oil return port (14) communicating with a lower space (12) that is a high-pressure space of the compressor (10). In the apparatus of FIG. 6, the emergency oil return passageway (88) is connected to the oil return port (14) instead of the suction pipe (16). The emergency oil outlet (82) of the oil separator (80) is disposed at a position higher than the oil return port (14). The refrigeration apparatus (100) according to the second modification is configured in substantially the same manner as the refrigeration apparatus (100) according to the first modification described with reference to FIG.
　図６の変形例２によると、油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きい緊急時には、潤滑油が、緊急油戻し通路（88）を通って、高圧の油分離器（80）から圧縮機（10）内の高圧の下部空間（12）に重力によって戻される。下部空間（12）に戻った潤滑油は、すぐに油溜まり（18）に加わるので、油溜まり（18）の潤滑油の量が早く回復し、油溜まり（18）における潤滑油中の冷媒濃度を素早く低下させることができる。また、潤滑油が高圧の空間に戻されるので、潤滑油が吸入側の低圧の空間に戻される場合に生じるような効率の低下が、緊急時であっても生じない。このため、高効率運転と信頼性の向上とを両立させることができる。 According to the modified example 2 of FIG. 6, in an emergency when the refrigerant concentration in the lubricating oil in the oil reservoir (18) is larger than a predetermined value, the lubricating oil passes through the emergency oil return passage (88) and passes through the high-pressure oil separator ( 80) is returned to the high pressure lower space (12) in the compressor (10) by gravity. The lubricating oil that has returned to the lower space (12) is immediately added to the oil sump (18), so the amount of lubricating oil in the oil sump (18) quickly recovers and the refrigerant concentration in the lubricating oil in the oil sump (18) is restored. Can be quickly reduced. Further, since the lubricating oil is returned to the high-pressure space, a reduction in efficiency that occurs when the lubricating oil is returned to the low-pressure space on the suction side does not occur even in an emergency. For this reason, it is possible to achieve both high-efficiency operation and improved reliability.
　本発明の多くの特徴及び優位性は、記載された説明から明らかであり、よって添付の特許請求の範囲によって、本発明のそのような特徴及び優位性の全てをカバーすることが意図される。更に、多くの変更及び改変が当業者には容易に可能であるので、本発明は、図示され記載されたものと全く同じ構成及び動作に限定されるべきではない。したがって、全ての適切な改変物及び等価物は本発明の範囲に入るものとされる。 Many features and advantages of the present invention will be apparent from the written description, and thus, it is intended by the appended claims to cover all such features and advantages of the present invention. Further, since many changes and modifications will readily occur to those skilled in the art, the present invention should not be limited to the exact construction and operation as illustrated and described. Accordingly, all suitable modifications and equivalents are intended to be within the scope of the present invention.
　以上説明したように、本発明は、油分離器を有する冷凍装置等について有用である。 As described above, the present invention is useful for a refrigeration apparatus having an oil separator.
１　冷媒回路
６　コントローラ
１０　圧縮機
１４　油戻し口
１６　吸入管
１８　油溜まり
１９　冷媒濃度センサ
２０　圧縮機構
２８　エジェクタ（吸込部）
８０　油分離器
８１　通常油取出口
８２　緊急油取出口
８６　通常油戻し通路
８７　制御機構
８８　緊急油戻し通路
８９　開閉弁
１００　冷凍装置 DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 6 Controller 10 Compressor 14 Oil return port 16 Suction pipe 18 Oil reservoir 19 Refrigerant concentration sensor 20 Compression mechanism 28 Ejector (suction part)
80 oil separator 81 normal oil outlet 82 emergency oil outlet 86 normal oil return passage 87 control mechanism 88 emergency oil return passage 89 on-off valve 100 refrigeration system

Claims (7)

  1. 　圧縮機（10）を含む冷媒回路（1）を有し、上記冷媒回路（1）で冷媒を循環させて冷凍サイクルを行う冷凍装置であって、
    　上記圧縮機（10）が吐出する冷媒から潤滑油を分離して貯留する油分離器（80）と、
    　上記油分離器（80）に貯留された潤滑油を上記圧縮機（10）に戻す通常油戻し通路（86）と、
    　上記油分離器（80）に貯留された潤滑油を上記圧縮機（10）に戻す緊急油戻し通路（88）と、
    　上記圧縮機（10）の油溜まり（18）における潤滑油中の冷媒濃度に対応する信号を出力する冷媒濃度センサ（19）と、
    　上記緊急油戻し通路（88）に設けられた開閉弁（89）と、
    　上記冷媒濃度センサ（19）の出力信号に基づいて上記開閉弁（89）を制御するコントローラ（6）とを備え、
    　上記油分離器（80）は、
    　上記通常油戻し通路（86）に接続されている通常油取出口（81）と、
    　上記通常油取出口（81）より下に形成され、上記緊急油戻し通路（88）に接続されている緊急油取出口（82）とを有し、
    　上記コントローラ（6）は、上記油溜まり（18）における潤滑油中の冷媒濃度が所定値より大きいことを上記冷媒濃度センサ（19）の出力信号が示す場合に、上記開閉弁（89）を開くように制御する
    ことを特徴とする冷凍装置。     A refrigeration apparatus having a refrigerant circuit (1) including a compressor (10) and performing a refrigeration cycle by circulating refrigerant in the refrigerant circuit (1),
    An oil separator (80) for separating and storing lubricating oil from the refrigerant discharged from the compressor (10);
    A normal oil return passage (86) for returning the lubricating oil stored in the oil separator (80) to the compressor (10);
    An emergency oil return passageway (88) for returning the lubricating oil stored in the oil separator (80) to the compressor (10);
    A refrigerant concentration sensor (19) for outputting a signal corresponding to the refrigerant concentration in the lubricating oil in the oil sump (18) of the compressor (10);
    An on-off valve (89) provided in the emergency oil return passage (88),
    A controller (6) for controlling the on-off valve (89) based on an output signal of the refrigerant concentration sensor (19),
    The oil separator (80)
    A normal oil outlet (81) connected to the normal oil return passage (86);
    An emergency oil outlet (82) formed below the normal oil outlet (81) and connected to the emergency oil return passage (88);
    The controller (6) opens the on-off valve (89) when the output signal of the refrigerant concentration sensor (19) indicates that the refrigerant concentration in the lubricating oil in the oil reservoir (18) is greater than a predetermined value. The refrigeration apparatus characterized by controlling as follows.
  2. 　請求項１において、
    　上記圧縮機（10）は、冷媒が流入する吸入管（16）を有し、
    　上記緊急油戻し通路（88）は、上記圧縮機（10）の上記吸入管（16）に接続されている
    ことを特徴とする冷凍装置。     In claim 1,
    The compressor (10) has a suction pipe (16) into which refrigerant flows,
    The refrigeration apparatus, wherein the emergency oil return passage (88) is connected to the suction pipe (16) of the compressor (10).
  3. 　請求項２において、
    　上記圧縮機（10）は、上記圧縮機（10）の高圧空間に潤滑油を吸い込む吸込部（28）を有し、
    　上記通常油戻し通路（86）は、上記吸込部（28）に接続されている
    ことを特徴とする冷凍装置。     In claim 2,
    The compressor (10) has a suction part (28) for sucking lubricating oil into the high-pressure space of the compressor (10),
    The refrigeration apparatus characterized in that the normal oil return passage (86) is connected to the suction part (28).
  4. 　請求項２において、
    　上記冷凍装置は、上記通常油戻し通路（86）に設けられた制御機構（87）を更に備え、
    　上記通常油戻し通路（86）は、上記圧縮機（10）の上記吸入管（16）に接続されており、
    　上記コントローラ（6）は、上記冷媒濃度センサ（19）の出力信号に基づいて上記通常油戻し通路(86)の潤滑油流量を制御する
    ことを特徴とする冷凍装置。     In claim 2,
    The refrigeration apparatus further includes a control mechanism (87) provided in the normal oil return passage (86),
    The normal oil return passage (86) is connected to the suction pipe (16) of the compressor (10),
    The controller (6) controls the flow rate of the lubricating oil in the normal oil return passage (86) based on the output signal of the refrigerant concentration sensor (19).
  5. 　請求項１において、
    　上記圧縮機（10）は、上記圧縮機（10）の高圧空間に連通する油戻し口（14）を有し、
    　上記緊急油戻し通路（88）は、上記油戻し口（14）に接続されており、上記油分離器（80）の上記緊急油取出口（82）は、上記油戻し口（14）より高い位置に配置されている
    ことを特徴とする冷凍装置。     In claim 1,
    The compressor (10) has an oil return port (14) communicating with the high-pressure space of the compressor (10),
    The emergency oil return passage (88) is connected to the oil return port (14), and the emergency oil outlet (82) of the oil separator (80) is higher than the oil return port (14). A refrigeration apparatus arranged in a position.
  6. 　請求項５において、
    　上記圧縮機（10）は、上記圧縮機（10）の高圧空間に潤滑油を吸い込む吸込部（28）を有し、
    　上記通常油戻し通路（86）は、上記吸込部（28）に接続されている
    ことを特徴とする冷凍装置。     In claim 5,
    The compressor (10) has a suction part (28) for sucking lubricating oil into the high-pressure space of the compressor (10),
    The refrigeration apparatus characterized in that the normal oil return passage (86) is connected to the suction part (28).
  7. 　請求項１において、
    　上記冷媒濃度センサ（19）は、静電容量式のセンサである
    ことを特徴とする冷凍装置。     In claim 1,
    The refrigerant concentration sensor (19) is a capacitance type refrigeration apparatus.
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