EP2161519A1 - Oil return algorithm for capacity modulated compressor - Google Patents

Oil return algorithm for capacity modulated compressor Download PDF

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Publication number
EP2161519A1
EP2161519A1 EP09251462A EP09251462A EP2161519A1 EP 2161519 A1 EP2161519 A1 EP 2161519A1 EP 09251462 A EP09251462 A EP 09251462A EP 09251462 A EP09251462 A EP 09251462A EP 2161519 A1 EP2161519 A1 EP 2161519A1
Authority
EP
European Patent Office
Prior art keywords
compressor
capacity
oil
motor
set forth
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.)
Withdrawn
Application number
EP09251462A
Other languages
German (de)
English (en)
French (fr)
Inventor
Gregory W. Hahn
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.)
Danfoss Scroll Technologies LLC
Original Assignee
Scroll Technologies 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 Scroll Technologies LLC filed Critical Scroll Technologies LLC
Publication of EP2161519A1 publication Critical patent/EP2161519A1/en
Withdrawn legal-status Critical Current

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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
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/02—Rotary-piston pumps specially adapted for elastic fluids of arcuate-engagement type, i.e. with circular translatory movement of co-operating members, each member having the same number of teeth or tooth-equivalents
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
    • 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
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F25B49/022—Compressor control 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
    • F25B2500/00—Problems to be solved
    • F25B2500/16—Lubrication

Definitions

  • This application relates to an algorithm for ensuring adequate oil return in a refrigerant system including a capacity modulated compressor.
  • Compressors are utilized as an integral part of a refrigerant system.
  • a compressor compresses a refrigerant and passes it downstream to a condenser.
  • Refrigerant from the condenser passes through an expansion device, and then through an evaporator. From the evaporator, the refrigerant returns to the compressor.
  • Lubricant is included in the refrigerant system, typically an Air Conditioner, Heat Pump or refrigeration application, and is particularly important to lubricate moving parts in the compressor.
  • the lubricant becomes entrained in the refrigerant, and can flow with the refrigerant throughout the refrigerant system. As such, there may sometimes be an inadequate supply of lubricant returned to the compressor. Lubricant can sit in other areas of the refrigerant system, and in particular in the condenser and evaporator.
  • compressor and refrigerant systems being of a variable capacity.
  • Typical applications of the compressor's ability to vary capacity include variable speed, multi-stepped modulation, PWM of compression element engagement, or other means of affecting capacity and the mass flow rates of the compressor.
  • the compressor may be operated at a lower capacity to improve energy efficiency. While operating at a higher capacity, the refrigerant may well drive sufficient lubricant back from the condenser and evaporator to the compressor such that there is an adequate lubricant supply. However, at lower capacities, it may sometimes be difficult to adequately drive the lubricant back.
  • One known system periodically provides an increase in speed when the compressor is operating at the lower speed.
  • the increased speed is maintained for a short period of time to drive lubricant back to the compressor.
  • the increase in speed is not tied to any existing conditions in the refrigerant system, and thus may be operated too frequently, or not frequently enough.
  • operating at the increased speed too frequency somewhat defeats the purpose of operating the compressor at the lower speed.
  • running at the higher speed to return lubricant too infrequently would be even more undesirable.
  • system conditions are monitored to predict an amount of oil migration from the compressor during low capacity operation.
  • an increased compressor capacity is run for a period of time.
  • a variable speed compressor is used as an example of a particular application of the invention.
  • a refrigerant system 20 is illustrated in Figure 1 .
  • a compressor shell 23 includes a lubricant sump 22, which maintains a quantity of lubricant.
  • a compressor pump unit 24 compresses refrigerant and delivers the refrigerant to a discharge tube 26. From the discharge tube 26, the lubricant passes through a condenser 28, an expansion device 30, an evaporator 32, and back through a suction tube 33 into the compressor shell 23.
  • a control 36 for a compressor motor 37 may operate the compressor motor 37 at various speeds.
  • the compressor may be operating at a relatively low speed to increase energy efficiency when a cooling demand is also low.
  • Sensors 34 and 35 monitor a condition, such as pressure, at the evaporator 32 and condenser 28, respectively.
  • sensors that monitor temperature or an estimated saturated refrigerant temperature can be used to detect the conditions the compressor is operating at, These conditions may be sent to the control 36 to assist in quantifying the amount of oil which has likely migrated outwardly of the compressor shell 23 into other system components at low speed operation.
  • the present invention integrates the amount of oil loss over time based upon a relationship such as shown in Figure 2 , and actuates the motor control 36 to increase the speed of the motor for a short period of oil return time when that integrated amount passes a particular limit.
  • the amount of oil loss is calculated and the speed is increased when the amount passes a limit.
  • the compressor speed may be ramped up from the low energy efficiency speed to a predetermined amount, e.g., 2400 rpm in a compressor having the characteristics as shown below, for a short period of time (e.g. 3 seconds).
  • the point at which the oil return speed-up will occur can be defined as a function of the pressure at the suction and discharge of the compressor, as a function of compressor capacity or based upon other variables.
  • a ten coefficient map can be utilized to set a curve similar to that shown in Figure 2 .
  • oil loss rate oz / hr a ⁇ 1 + a ⁇ 2 PE + a ⁇ 3 PC + a ⁇ 4 ⁇ PE 2 + a ⁇ 5 PE ⁇ PC + a ⁇ 6 ⁇ PC 2 + a ⁇ 7 ⁇ PE 3 + a ⁇ 8 ⁇ PE 2 PC + a ⁇ 9 PE ⁇ PC 2 + a ⁇ 10 ⁇ PC 3 .
  • the oil loss rate shown above is based upon the pressure at the evaporator and the pressure at the condenser.
  • the same form of equation could be applied to evap and condensing temperatures. It could also be multiplied by a multiplier which brings in a capacity level factor.
  • variable speed compressors this would be the current rpm/max RPM.
  • the quantity of oil which is "lost" or which has migrated from the compressor is calculated, or integrated, over time while the compressor is operating at a low capacity. Once that quantity exceeds a predetermined limit, then the compressor capacity is ramped up to the oil return speed for a short period of time.
  • the amount of oil lost is calculated in a plurality of discrete time units when the compressor is operating at a lower speed. As an example, this can occur every five seconds.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Compressor (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
EP09251462A 2008-09-03 2009-06-01 Oil return algorithm for capacity modulated compressor Withdrawn EP2161519A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12/203,164 US20100050673A1 (en) 2008-09-03 2008-09-03 Oil return algorithm for capacity modulated compressor

Publications (1)

Publication Number Publication Date
EP2161519A1 true EP2161519A1 (en) 2010-03-10

Family

ID=41202660

Family Applications (1)

Application Number Title Priority Date Filing Date
EP09251462A Withdrawn EP2161519A1 (en) 2008-09-03 2009-06-01 Oil return algorithm for capacity modulated compressor

Country Status (5)

Country Link
US (1) US20100050673A1 (zh)
EP (1) EP2161519A1 (zh)
JP (1) JP2010059962A (zh)
KR (1) KR20100027946A (zh)
CN (1) CN101666305B (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110986430A (zh) * 2019-12-31 2020-04-10 珠海格力电器股份有限公司 一种有效回油控制方法、装置及空调机组
WO2023036614A1 (de) * 2021-09-10 2023-03-16 BSH Hausgeräte GmbH Betreiben eines drehzahlgesteuerten verdichters eines haushalts-kältegeräts

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2853742B1 (en) * 2013-09-27 2016-04-20 Emerson Climate Technologies GmbH Method and apparatus for oil sensing in a compressor
US10473377B2 (en) 2016-09-26 2019-11-12 Carrier Corporation High outdoor ambient and high suction pressure oil pump out mitigation for air conditioners
KR102388890B1 (ko) * 2017-10-12 2022-04-22 한온시스템 주식회사 압축기 제어 방법

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5067326A (en) * 1979-07-31 1991-11-26 Alsenz Richard H Method and apparatus for controlling capacity of a multiple-stage cooling system
US20030051494A1 (en) * 2001-09-20 2003-03-20 Shigeki Ohya Refrigerant cycle system including two evaporators
US20080134701A1 (en) * 2006-12-12 2008-06-12 Ole Moelgaard Christensen Variable Compressor Oil Return

Family Cites Families (11)

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Publication number Priority date Publication date Assignee Title
JPS62106255A (ja) * 1985-10-31 1987-05-16 株式会社東芝 冷凍サイクルの能力制御装置
JP2782858B2 (ja) * 1989-10-31 1998-08-06 松下電器産業株式会社 スクロール気体圧縮機
US5417078A (en) * 1994-06-13 1995-05-23 Carrier Corporation Refrigerator flow control apparatus
US20050103035A1 (en) * 2003-11-19 2005-05-19 Massachusetts Institute Of Technology Oil circulation observer for HVAC systems
US6981384B2 (en) * 2004-03-22 2006-01-03 Carrier Corporation Monitoring refrigerant charge
JP4457792B2 (ja) * 2004-07-20 2010-04-28 株式会社デンソー 冷凍サイクル装置
US20080314057A1 (en) * 2005-05-04 2008-12-25 Alexander Lifson Refrigerant System With Variable Speed Scroll Compressor and Economizer Circuit
EP1893923A4 (en) * 2005-06-07 2012-05-30 Carrier Corp CONTROL FOR COMPRESSOR MOTOR WITH VARIABLE SPEED CONTROL FOR LOW SPEED OPERATION
JP4881666B2 (ja) * 2006-07-07 2012-02-22 日立アプライアンス株式会社 横型スクロール圧縮機
WO2008024110A1 (en) * 2006-08-22 2008-02-28 Carrier Corporation Improved oil return in refrigerant system
US8904814B2 (en) * 2008-06-29 2014-12-09 Bristol Compressors, International Inc. System and method for detecting a fault condition in a compressor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5067326A (en) * 1979-07-31 1991-11-26 Alsenz Richard H Method and apparatus for controlling capacity of a multiple-stage cooling system
US20030051494A1 (en) * 2001-09-20 2003-03-20 Shigeki Ohya Refrigerant cycle system including two evaporators
US20080134701A1 (en) * 2006-12-12 2008-06-12 Ole Moelgaard Christensen Variable Compressor Oil Return

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110986430A (zh) * 2019-12-31 2020-04-10 珠海格力电器股份有限公司 一种有效回油控制方法、装置及空调机组
WO2023036614A1 (de) * 2021-09-10 2023-03-16 BSH Hausgeräte GmbH Betreiben eines drehzahlgesteuerten verdichters eines haushalts-kältegeräts

Also Published As

Publication number Publication date
US20100050673A1 (en) 2010-03-04
CN101666305B (zh) 2014-12-03
CN101666305A (zh) 2010-03-10
JP2010059962A (ja) 2010-03-18
KR20100027946A (ko) 2010-03-11

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