US3719057A - Two-stage refrigeration system having crankcase pressure regulation in high stage compressor - Google Patents

Two-stage refrigeration system having crankcase pressure regulation in high stage compressor Download PDF

Info

Publication number
US3719057A
US3719057A US00187800A US3719057DA US3719057A US 3719057 A US3719057 A US 3719057A US 00187800 A US00187800 A US 00187800A US 3719057D A US3719057D A US 3719057DA US 3719057 A US3719057 A US 3719057A
Authority
US
United States
Prior art keywords
stage
chamber
pressure
crankcase
suction chamber
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
US00187800A
Other languages
English (en)
Inventor
W Grant
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Copeland Industrial LP
Original Assignee
Vilter Manufacturing LLC
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 Vilter Manufacturing LLC filed Critical Vilter Manufacturing LLC
Application granted granted Critical
Publication of US3719057A publication Critical patent/US3719057A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F25B1/10—Compression machines, plants or systems with non-reversible cycle with multi-stage compression

Definitions

  • ABSTRACT A two-stage refrigeration system including a condensor, a receiver, an evaporator, a low-stage dry-wall compressor and a high-stage dry-wall compressor, the low-stage compressor including an oil-draining assembly for automatically draining oil from the suction chamber to the crankcase chamber, and a pressureequalizing connection between the suction chamber and the crankcase chamber, the high-stage compressor having an oil-draining assembly for automatically draining oil from the high-stage suction chamber to the high-stage crankcase chamber, and a pressure con- INTER COOLER PATENTEDMAR' 5 I973 FIGJ EVA PO RATO R CONDENSER RECEIVER COOLER INTER- INVENTOR -B/IN?
  • the two-stage refrigeration system of the present invention contemplates the use of drywall compressors and reduces the possibility of oil vapors being carried into the compressor suction and discharge chambers to a minimum.
  • Ser. No. 187,801 entitled Single Stage Dry Cylinder Compressor Having Automatic Oil Drain from Suction Chamber to Crankcase, an automatic oil draining assembly has been disclosed'for a single-stage drywall compressor.
  • the pressure in the high-stage suction chamber and high-stage crankcase chamber is maintained at a predetermined pressure differential to eliminate overloading of the compressor bearings and piston rod and to assure that gas pressure leakage is from the high-stage suction chamber into the high-stage crankcase chamber.
  • FIG. 1 is a schematic diagram of the two-stage drywall compressor refrigeration system of the present invention.
  • FIG. 2 is an electrical diagram of the circuit arrangement for the oil return assemblies.
  • FIG. 1 of the drawings A refrigeration system as contemplated herein is shown in FIG. 1 of the drawings and as seen therein, the refrigeration system includes a low-stage compressor 10, a high-stage compressor 12, a condenser 14, a receiver 16, and an evaporator 18.
  • the low-stage compressor 10 is connected to the high-stage compressor 12 by means of a discharge conduit 20.
  • the high-stage compressor 12 is serially connected to the low-stage compressor 10 through the condenser 14, receiver 16 and evaporator 18 by means of high-pressure discharge conduit 22, liquid refrigerant conduit 24, high-pressure refrigerant conduit 26 and suction pressure conduit 28.
  • a refrigerator control valve 25 is provided in conduit 28 to reduce pressure at the entrance of the evaporator.
  • Low-Stage Compressor The low-stage compressor 10 includes a low-stage discharge chamber 30, a low-stage suction chamber 32, and a low-stage crankcase chamber 34. Means are provided to equalize the pressure between the suction chamber 32 and crankcase chamber 34 in the form of an equalizing line 36. Oil vapor is prevented from entering the suction chamber through the equalizing line 36 by means of an oil filtering device 38.
  • Means are provided to automatically drain oil from the suction chamber 32 back to the crankcase chamber 34, as more fully discussed in my copending application Ser. 187,801.
  • Such means is in the form of an automatic oil return assembly 40 which includes a reservoir 42L operatively connected to allow oil to flow from the suction chamber 32 to the reservoir 42L by oil conduits 44 and operatively connected to allow oil to flow from the reservoir 42L to the crankcase chamber 34 by oil conduit 46.
  • One-way check valves 48L and 50L are provided, respectively, in the oil conduits 44L and 46L to prevent reverse flow of oil through either of the conduits 44 or 46.
  • the flow of oil from the suction chamber to the reservoir 4.2 is controlled by means of a solenoid valve 52L interposed in a pressure line 54 provided between the suction chamber and the reservoir 42.
  • the solenoid valve is normally open to equalize pressure between the suction chamber 32 and the reservoir 42L to allow any oil which accumulates in the suction chamber 32 to flow freely through the oil conduits 44 to the reservoir 42L.
  • Oil is forced from the reservoir 42L through the conduit 46L and into the crankcase chamber 34 by connecting the reservoir 42 to the discharge conduit 20 by conduit 56 to allow the high-pressure discharge refrigerant to enter the reservoir 42L.
  • the flow of highpressure' refrigerant is controlled by means of a second solenoid valve 58L interposed in the conduit 56, which is normally closed when solenoid valve 52L is open.
  • solenoid valve SSL When solenoid valve SSL is opened, solenoid valve 52L is closed and the pressure in conduit 56 and reservoir 42 rises to force the oil through the oil conduit 46 into the crankcase chamber.
  • the rate of pressure rise in the reservoir 42 can be restricted by means of a restricted orifice 60 provided in conduit 56.
  • Means are provided to selectively control the solenoids 52L and SSL in response to the level of oil in the reservoir 42L.
  • Such means is in the form of a float valve 62L provided in the reservoir and operatively connected through a circuit as shown in FIG. 2 to the solenoids 52 and 58 to close the solenoid 52 and open the solenoid 58 whenever the oil in the reservoir reaches a predetermined height.
  • the operation of the electrical circuit in FIG. 2 isdescribed below.
  • the high-stage compressor 12 includes a high-stagedischarge chamber 64, a high-stage suction chamber 66 and a crankcase chamber 68. Means are provided to allow for the flow of oil from the suction chamber 66 to the high-stage crankcase chamber 68 in the form of an oil-return assembly 70.
  • the assembly 70 operates in substantially the same manner as oil-return assembly 40.
  • the flow of oil from the suction chamber 66 to the reservoir 421-! is controlled by means of a solenoid valve 52H interposed in a pressure line 54H provided between the suction chamber 66 and the reservoir 42H.
  • the solenoid valve 52H is normally open to equalize pressure between suction chamber 66 and the reservoir 42H to allow any oil which accumulates in the suction chamber 66 to flow freely through the oil conduits 44H to the reservoir 42H.
  • Oil is forced from the reservoir 42H through the conduit 46H into the crankcase chamber 68 by connecting the reservoir 421-] to the discharge conduit 20 by a gas pressure conduit 56H to allow the high-pressure discharge refrigerant to enter the reservoir 421-1.
  • the flow of high-pressure refrigerant is controlled by means of a second solenoid valve 58H interposed in the conduit 561-! which is normally closed when solenoid valve 521-! is open.
  • solenoid valve 58H When solenoid valve 58H is opened, solenoid valve 52H is closed and the pressure of the gaseous refrigerant in the conduit 56B is applied to the reservoir 42H to force the oil into the crankcase chamber 68.
  • the rate of pressure rise in the reservoir 42H is restricted by means of an orifice 60 provided in conduit 56H.
  • Means are provided to selectively control the solenoids 52H and 581-! in response to the level of oil in the reservoir 42H.
  • Such means is in the form of a float 1 valve 62H provided in the reservoir 42H and operatively connected through the circuit shown in FIG. 2 to the solenoids 52H and 58H.
  • the float valve will deenergize solenoid 521-! to close conduit 54H and will open solenoid 58H and connect the reservoir 42H to the high-pressure discharge chamber 64.
  • Control Circuit The control circuit for the two oil drain assemblies and 70 are identical as seen in FIG. 2. The description of the circuit for controlling solenoids 52L and 58L is therefore described below.
  • the description for the circuit for solenoids 52H and 581-! is the same.
  • the float control valve 62L is connected across lines L,-L, in series with timer 80 by lines 82.
  • the solenoids 521. and 58L are alternately connected across the lines L L, by timer switch 84 connected to line 86.
  • a holding circuit is set up between the timer 80 and the solenoid 58L by a bypass line 88.
  • the solenoid valve 52L is normally energized by closed switch 84.
  • switch 84 When the float valve 62L closes to energize timer 80, switch 84 will open the circuit through solenoid 52L and close the circuit through solenoid 58L.
  • the timer 80 will run for a preset time interval to allow for the complete discharge of oil from the reservoir 42L since the float valve 62L will open as soon as oil starts to drain from reservoir 42L.
  • the solenoids 58L and timer 80 will be deenergized and solenoid 52L will be energized.
  • the pressure differential between the high-pressure suction chamber 66 and the high-pressure crankcase chamber 68 is controlled by means of a pilot-operated pressure-regulating valve 72.
  • the crankcase chamber 68 is connected to the low-pressure crankcase chamber 34 by means of-a gas pressure conduit 74.
  • the low-pressure discharge chamber 30 is connected to the highpressure suction chamber 66 by means of the gas pressure conduit 20.
  • An intercooler 76 may be provided in the discharge pressure conduit 20, if desired.
  • the pilot-operated pressure-regulating valve is interposed in the gas pressure conduit 74 and is operatively connected to the discharge pressure conduit 20 by means of a bypass conduit 78.
  • the pilot-operated pressure-regulating valve 72 is set to maintain the pressure in the high-pressure crankcase chamber 68 approximately 1 pound per square inch below the pressure of the high-pressure suction chamber 66. By maintaining this pressure differential at 1 pound per square inch, any oil vapor present in the high-pressure crankcase chamber 68 will be prevented from flowing into the high-pressure suction chamber 66. Since a one-pound pressure differential always exists between the highstage suction chamber 66 and the high-stage crankcase chamber 68, a continual internal leakage of gas will occur between the suction chamber 66 and crankcase chamber 68.
  • the pressure-regulating valve 72 will constantly bleed crankcase chamber pressure from crankcase chamber 68 to crankcase chamber 34 at the same rate as the internal leakage between the suction chamber 66 and the crankcase chamber 68.
  • the internal leakage will increase and the pressure-regulating valve will close until the pressure in the crankcase chamber 68 builds up to within one pound of the pressure in the suction chamber 66 at which point the pressure-regulating valve 72 will again open.
  • the pressure-regulating valve will open wide to immediately reduce the pressure in crankcase chamber 68 to one pound below the pressure in suction chamber 66.
  • the high-stage crankcase chamber 64 is connected to the low-stage crankcase chamber 34 to prevent any loss of oil from the system.
  • the oil vapor within the crankcase chamber 68 will pass to the crankcase chamber 34. It should be apparent that with this arrangement oil will accumulate in chamber 34 and the oil level in chamber 68 will creep below normal. This can be compensated for by connecting an oil pump to respond to the oil level in chamber 34 and to pump oil from chamber 34 to chamber 68.
  • the present invention provides for an oil-free operation of a two-stage drywall compressor for a refrigeration system. This is accomplished by holding the pressure in the high-stage suction chamber higher than the pressure in the high-stage crankcase chamber. This pressure differential is controlled by a pressure-regulat- 1 ing valve which is connected to respond to the suction chamber pressure and the crankcase chamber pressure. Internal gas pressure leakage in the high-stage compressor will always be from the suction chamber to the crankcase chamber.
  • a refrigeration system comprising,
  • each compressor including a discharge chamber, a suction chamber and a crankcase chamber,
  • said maintaining means includes a pressure-responsive valve connected to vent said high-stage crankcase chamber and connected to respond to the discharge pressure of said low-stage discharge chamber.
  • valve is set to maintain a one-pound pressure differential between the high-stage suction chamber and the high-stage crankcase chamber.
  • each of said oil-draining means includes a reservoir operatively connected to allow oil to drain from the corresponding suction chamber to the reservoir and from the reservoir to the corresponding crankcase chamber and including means responsive to the level of oil in the reservoir for selectively connecting said reservoir in gas-pressure equalizing relation to one of the corresponding suction chambers or discharge chambers.
  • the system according to claim 1 including a first gas pressure conduit connected between said highstage crankcase chamber and said low-stage crankcase chamber, and a second gas pressure conduit connected between said low-stage discharge chamber and said high-stage suction chamber, said maintaining means in- 0 eluding a pressure-responsive regulating valve interposed in said first gas pressure conduit and connected to said second gas pressure conduit.
  • valve is set to maintain the pressure in said high-stage suction chamber higher than the pressure in said highstage crankcase chamber.
  • a refrigeration system having a condenser, a
  • first stage drywall compressor including a first stage suction chamber, a first stage discharge chamber and a first stage crankcase chamber
  • second stage drywall compressor including a second stage suction chamber, a second stage discharge chamber, and a second stage crankcase chamber
  • a gas refrigerant conduit connecting said first stage discharge chamber in gas pressure relation to said second stage suction chamber
  • a gas pressure conduit connecting said second stage crankcase chamber in gas pressure relation to said low-stage crankcase chamber
  • controlling means in connected to said gas refrigerant conduit to maintain a predetermined pressure differential between said second-stage suction chamber and said second-stage crankcase chamber.
  • the system according to claim 7 including means for equalizing pressure between said first-stage suction chamber and said first-stage crankcase chamber, first means operatively connected to said first-stage suction chamber and said first-stage discharge chamber for draining oil from said first-stage suction chamber and discharging oil under pressure into said first-stage crankcase chamber, and second means operatively connected to said second-stage discharge chamber and said second stage suction chamber for automatically draining oil from said second-stage suction chamber and discharging oil into said second stage crankcase chamber.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
US00187800A 1971-10-08 1971-10-08 Two-stage refrigeration system having crankcase pressure regulation in high stage compressor Expired - Lifetime US3719057A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18780071A 1971-10-08 1971-10-08

Publications (1)

Publication Number Publication Date
US3719057A true US3719057A (en) 1973-03-06

Family

ID=22690521

Family Applications (1)

Application Number Title Priority Date Filing Date
US00187800A Expired - Lifetime US3719057A (en) 1971-10-08 1971-10-08 Two-stage refrigeration system having crankcase pressure regulation in high stage compressor

Country Status (5)

Country Link
US (1) US3719057A (online.php)
JP (1) JPS5434169B2 (online.php)
AU (1) AU455400B2 (online.php)
FR (1) FR2156140B1 (online.php)
IT (1) IT965492B (online.php)

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4411141A (en) * 1981-02-06 1983-10-25 Mitsubishi Denki Kabushiki Kaisha Parallel operation compressor type refrigerating apparatus
US4551989A (en) * 1984-11-30 1985-11-12 Gulf & Western Manufacturing Company Oil equalization system for refrigeration compressors
US4822259A (en) * 1985-06-14 1989-04-18 Basseggio Narcizo O System of compressing miscible fluids
US4951475A (en) * 1979-07-31 1990-08-28 Altech Controls Corp. Method and apparatus for controlling capacity of a multiple-stage cooling system
US5150586A (en) * 1989-11-16 1992-09-29 Basseggio Narcizo O System and process of compressing miscible fluids
US5522233A (en) * 1994-12-21 1996-06-04 Carrier Corporation Makeup oil system for first stage oil separation in booster system
US5586450A (en) * 1995-09-25 1996-12-24 Carrier Corporation Plural compressor oil level control
WO1997043585A1 (en) * 1996-05-10 1997-11-20 Shaw David N Series connected primary and booster compressors
US5927088A (en) * 1996-02-27 1999-07-27 Shaw; David N. Boosted air source heat pump
US6276148B1 (en) 2000-02-16 2001-08-21 David N. Shaw Boosted air source heat pump
US20040216484A1 (en) * 2003-03-26 2004-11-04 Haruhisa Yamasaki Refrigerant cycle apparatus
US20050044866A1 (en) * 2003-08-27 2005-03-03 Shaw David N. Boosted air source heat pump
US20060073026A1 (en) * 2004-10-06 2006-04-06 Shaw David N Oil balance system and method for compressors connected in series
US20080173034A1 (en) * 2007-01-19 2008-07-24 Hallowell International, Llc Heat pump apparatus and method
US20090229300A1 (en) * 2005-11-30 2009-09-17 Daikin Industries, Ltd. Refrigeration System
US20100242529A1 (en) * 2007-11-30 2010-09-30 Daikin Industries, Ltd. Refrigeration apparatus
US20100251761A1 (en) * 2007-11-30 2010-10-07 Daikin Industries, Ltd. Refrigeration apparatus
US20100251741A1 (en) * 2007-11-30 2010-10-07 Daikin Industries, Ltd. Refrigeration apparatus
US20100257894A1 (en) * 2007-11-30 2010-10-14 Daikin Industries, Ltd. Refrigeration apparatus
US20100300141A1 (en) * 2007-11-30 2010-12-02 Daikin Industries, Ltd. Refrigeration apparatus
US20120227426A1 (en) * 2011-03-10 2012-09-13 Streamline Automation, Llc Extended Range Heat Pump
EP2990739A1 (en) * 2014-08-29 2016-03-02 BI Freezer Srl Process for the external force-feed lubrication of refrigerating compressors
US10782053B1 (en) 2018-05-09 2020-09-22 Otg, Llc Single stage, single phase, low pressure refrigeration system
US11137180B1 (en) * 2020-04-30 2021-10-05 Trane Air Conditioning Systems (China) Co., Ltd. System and method for OCR control in paralleled compressors
US11300328B2 (en) * 2018-12-19 2022-04-12 Emerson Climate Technologies, Inc. Oil control for climate-control system
US11415342B2 (en) * 2018-09-28 2022-08-16 Daikin Industries, Ltd. Multistage compression system
US11604018B1 (en) 2018-05-09 2023-03-14 Otg, Llc Low pressure refrigeration system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT378600B (de) * 1983-05-24 1985-08-26 Wein Gedeon Waermerueckgewinnungseinrichtung fuer eine kompressor-kuehlanlage

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2606430A (en) * 1951-08-24 1952-08-12 Freezing Equipment Sales Inc Automatic lubrication means for plural stage compressors
US2646212A (en) * 1950-11-30 1953-07-21 Edward P Kellie Oil level equalizing device for multiple compressor arrangement
US3494137A (en) * 1968-06-12 1970-02-10 George K Cargo Fluid-operated pump and refrigerant system containing the same
US3500962A (en) * 1969-05-01 1970-03-17 Vilter Manufacturing Corp Lubrication system for compressors

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3543880A (en) * 1969-07-07 1970-12-01 Vilter Manufacturing Corp Two stage refrigeration compressor having automatic oil drain for the first stage suction chamber

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2646212A (en) * 1950-11-30 1953-07-21 Edward P Kellie Oil level equalizing device for multiple compressor arrangement
US2606430A (en) * 1951-08-24 1952-08-12 Freezing Equipment Sales Inc Automatic lubrication means for plural stage compressors
US3494137A (en) * 1968-06-12 1970-02-10 George K Cargo Fluid-operated pump and refrigerant system containing the same
US3500962A (en) * 1969-05-01 1970-03-17 Vilter Manufacturing Corp Lubrication system for compressors

Cited By (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4951475A (en) * 1979-07-31 1990-08-28 Altech Controls Corp. Method and apparatus for controlling capacity of a multiple-stage cooling system
US4411141A (en) * 1981-02-06 1983-10-25 Mitsubishi Denki Kabushiki Kaisha Parallel operation compressor type refrigerating apparatus
US4551989A (en) * 1984-11-30 1985-11-12 Gulf & Western Manufacturing Company Oil equalization system for refrigeration compressors
US4822259A (en) * 1985-06-14 1989-04-18 Basseggio Narcizo O System of compressing miscible fluids
US4895498A (en) * 1985-06-14 1990-01-23 Basseggio Narcizo O Crank case chamber
US5150586A (en) * 1989-11-16 1992-09-29 Basseggio Narcizo O System and process of compressing miscible fluids
US5522233A (en) * 1994-12-21 1996-06-04 Carrier Corporation Makeup oil system for first stage oil separation in booster system
JP2848813B2 (ja) 1995-09-25 1999-01-20 キャリア コーポレイション 冷却回路
US5586450A (en) * 1995-09-25 1996-12-24 Carrier Corporation Plural compressor oil level control
US5927088A (en) * 1996-02-27 1999-07-27 Shaw; David N. Boosted air source heat pump
WO1997043585A1 (en) * 1996-05-10 1997-11-20 Shaw David N Series connected primary and booster compressors
US5839886A (en) * 1996-05-10 1998-11-24 Shaw; David N. Series connected primary and booster compressors
US6276148B1 (en) 2000-02-16 2001-08-21 David N. Shaw Boosted air source heat pump
USRE39625E1 (en) 2000-02-16 2007-05-15 Hallowell International, Llc Boosted air source heat pump
US20040216484A1 (en) * 2003-03-26 2004-11-04 Haruhisa Yamasaki Refrigerant cycle apparatus
US7111471B2 (en) * 2003-03-26 2006-09-26 Sanyo Electric Co., Ltd. Refrigerant cycle apparatus
US20050044866A1 (en) * 2003-08-27 2005-03-03 Shaw David N. Boosted air source heat pump
US6931871B2 (en) 2003-08-27 2005-08-23 Shaw Engineering Associates, Llc Boosted air source heat pump
US20090007588A1 (en) * 2004-10-06 2009-01-08 David Shaw Oil Balance System and Method for Compressors
US7712329B2 (en) 2004-10-06 2010-05-11 David Shaw Oil balance system and method for compressors
US8075283B2 (en) 2004-10-06 2011-12-13 Hallowell International, Llc Oil balance system and method for compressors connected in series
US20080283133A1 (en) * 2004-10-06 2008-11-20 Hallowell International, Llc Oil balance system and method for compressors connected in series
US20060073026A1 (en) * 2004-10-06 2006-04-06 Shaw David N Oil balance system and method for compressors connected in series
US20080085195A1 (en) * 2004-10-06 2008-04-10 Hallowell International, Llc Oil balance system and method for compressors connected in series
US7651322B2 (en) 2004-10-06 2010-01-26 Hallowell International, Llc Oil balance system and method for compressors connected in series
US7918106B2 (en) * 2005-11-30 2011-04-05 Daikin Industries, Ltd. Refrigeration system
US20090229300A1 (en) * 2005-11-30 2009-09-17 Daikin Industries, Ltd. Refrigeration System
US20080173034A1 (en) * 2007-01-19 2008-07-24 Hallowell International, Llc Heat pump apparatus and method
US8356490B2 (en) * 2007-11-30 2013-01-22 Daikin Industries, Ltd. Refrigeration apparatus
US8387411B2 (en) * 2007-11-30 2013-03-05 Daikin Industries, Ltd. Refrigeration apparatus
US20100300141A1 (en) * 2007-11-30 2010-12-02 Daikin Industries, Ltd. Refrigeration apparatus
US20100251741A1 (en) * 2007-11-30 2010-10-07 Daikin Industries, Ltd. Refrigeration apparatus
US20100251761A1 (en) * 2007-11-30 2010-10-07 Daikin Industries, Ltd. Refrigeration apparatus
US20100257894A1 (en) * 2007-11-30 2010-10-14 Daikin Industries, Ltd. Refrigeration apparatus
US8327661B2 (en) * 2007-11-30 2012-12-11 Daikin Industries, Ltd. Refrigeration apparatus
US8327662B2 (en) * 2007-11-30 2012-12-11 Daikin Industries, Ltd. Refrigeration apparatus
US20100242529A1 (en) * 2007-11-30 2010-09-30 Daikin Industries, Ltd. Refrigeration apparatus
US20120227426A1 (en) * 2011-03-10 2012-09-13 Streamline Automation, Llc Extended Range Heat Pump
US8966916B2 (en) * 2011-03-10 2015-03-03 Streamline Automation, Llc Extended range heat pump
EP2990739A1 (en) * 2014-08-29 2016-03-02 BI Freezer Srl Process for the external force-feed lubrication of refrigerating compressors
US10782053B1 (en) 2018-05-09 2020-09-22 Otg, Llc Single stage, single phase, low pressure refrigeration system
US11604018B1 (en) 2018-05-09 2023-03-14 Otg, Llc Low pressure refrigeration system
US11415342B2 (en) * 2018-09-28 2022-08-16 Daikin Industries, Ltd. Multistage compression system
US11300328B2 (en) * 2018-12-19 2022-04-12 Emerson Climate Technologies, Inc. Oil control for climate-control system
US11137180B1 (en) * 2020-04-30 2021-10-05 Trane Air Conditioning Systems (China) Co., Ltd. System and method for OCR control in paralleled compressors
US11649996B2 (en) 2020-04-30 2023-05-16 Trane Air Conditioning Systems (China) Co., Ltd. System and method for OCR control in paralleled compressors

Also Published As

Publication number Publication date
AU455400B2 (en) 1974-11-21
IT965492B (it) 1974-01-31
JPS4845913A (online.php) 1973-06-30
JPS5434169B2 (online.php) 1979-10-25
FR2156140B1 (online.php) 1976-01-30
FR2156140A1 (online.php) 1973-05-25
AU4672272A (en) 1974-03-21

Similar Documents

Publication Publication Date Title
US5236311A (en) Compressor device for controlling oil level in two-stage high dome compressor
US5094598A (en) Capacity controllable compressor apparatus
US4180986A (en) Refrigeration system on/off cycle
US5603227A (en) Back pressure control for improved system operative efficiency
US4335582A (en) Unloading control system for helical screw compressor refrigeration system
US5522233A (en) Makeup oil system for first stage oil separation in booster system
US3481152A (en) Condenser head pressure control system
GB939304A (en) Control mechanism for gas compression means
US5134856A (en) Oil pressure maintenance for screw compressor
US3119550A (en) Compressor capacity control
US2606430A (en) Automatic lubrication means for plural stage compressors
US2076332A (en) Lubrication system
US2178100A (en) Refrigerating condensing unit
US2165741A (en) Compressor unloader
US2032286A (en) Refrigerant liquid return system
US2089630A (en) Refrigerating apparatus
US2646212A (en) Oil level equalizing device for multiple compressor arrangement
US2518212A (en) Refrigeration control valve
GB1098030A (en) Compressor lubrication system
US3033009A (en) Multiple compressor system for refrigeration installation
US3074619A (en) Method of and means for combined operation of automatically capacity regulated compressors
US7231783B2 (en) Oil control system for a refrigeration system
US3724231A (en) Single stage dry cylinder compressor having automatic oil drain from suction chamber to crankcase
JPS62135691A (ja) 冷却または加熱ポンプ装置用の調整装置
US1671984A (en) Variable capacity compressor