WO2010115435A1 - Refrigerating circuit and method for controlling the oil distribution within the same - Google Patents
Refrigerating circuit and method for controlling the oil distribution within the same Download PDFInfo
- Publication number
- WO2010115435A1 WO2010115435A1 PCT/EP2009/002529 EP2009002529W WO2010115435A1 WO 2010115435 A1 WO2010115435 A1 WO 2010115435A1 EP 2009002529 W EP2009002529 W EP 2009002529W WO 2010115435 A1 WO2010115435 A1 WO 2010115435A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- compressor
- oil
- compressors
- refrigerating circuit
- threshold value
- Prior art date
Links
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
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/07—Details of compressors or related parts
- F25B2400/075—Details of compressors or related parts with parallel compressors
Definitions
- the invention is related to a refrigerating circuit as well as to a method for control- ling the oil distribution within a multi-compressor unit of a refrigerating circuit.
- a refrigerating circuit com- prises - in flow direction - a multi-compressor unit, a condenser/gas cooler, a receiver, at least one evaporator having a respective expansion device arranged before it, and conduits circulating a refrigerant containing oil therethrough
- the multi-compressor unit comprises a first compressor the rotational speed of which can be controlled and at least one further compressor running at a constant rota- tional speed, wherein the suction sides and the pressure sides of the compressors are connected in parallel, wherein an oil balance line is provided between the oil sumps of the compressors, said oil balance line connecting the oil sumps of the compressors at substantially the same positions of height, and wherein a solenoid valve al- lowing oil flow in either direction is arranged in the oil balance line between the first compressor and the at least one further compressor for controlling the oil distribution between the oil sumps of the compressors during operation of the compressors of the multi-compressor unit.
- a method for controlling the oil distribution within a multi-compressor unit of a refrigerating circuit comprises a multi-compressor unit having a first compressor the rotational speed of which is controllable and at least one further compressor running at constant speed, wherein the suction sides and the pressure sides of the compressors are connected in parallel, comprising the following steps carried out while all compressors of the multi-compressor unit are running:
- a method for controlling the oil distribution within a multi-compressor unit of a refrigerating circuit comprises a multi-compressor unit having a first compressor the rotational speed of which is controllable and at least one further compressor running at constant speed, wherein the suction sides and the pressure sides of the compressors are connected in parallel, comprising the following steps carried out while all compressors of the multi-compressor unit are running:
- FIG. 1 shows a schematic diagram of a refrigeration circuit applying a multi- compressor unit according to an embodiment of the invention.
- the refrigeration circuit 2 comprises in flow direction a multi-compressor unit having a speed controlled compressor 4, a first constant speed compressor 6 and a second constant speed compressor 8, a condenser/gas cooler 12, a receiver/collecting container 14, three evaporators 18, 22 and 26 having a respective expansion valve 16, 20 and 24 arranged before it and conduits/piping circulating a refrigerant containing oil therethrough.
- the operation of the refrigeration circuit 2 is known to a skilled person and does not need to be explained further.
- suction line 28 The conduit portion connecting the outputs of the evaporators 18, 22 and 26 to the input sides of the compressors 4, 6 and 8 is called suction line 28 hereinafter.
- the suction line 28 branches off into three separate parallel lines leading to the input sides of the compressors 4, 6 and 8. The suction sides of the compressors 4, 6 and 8 are therefore connected in parallel.
- the compressors 4, 6 and 8 can be reciprocating compressors.
- the speed controlled compressor 4 can be a VSD-controlled compressor.
- the conduit portion between the output sides of the compressors 4, 6 and 8 and the entrance of the condenser/gas cooler 12 is called pressure line 10 hereinafter.
- the pressure line portions from the output sides of the compressors 4, 6 and 8 join before the condenser/gas cooler 12. Hence, the pressure side of the compressors 4, 6 and 8 are also connected in parallel.
- the refrigerant flow direction through these elements of the refrigerating circuit 2 is schematically depicted by an arrow having the reference numeral 38.
- the condenser/gas cooler 12 works as a condenser liquefying the refrigerant, if the refrigeration circuit 2 is operated in a sub-critical mode.
- the condenser/gas cooler 12 works as a gas cooler not liquefying but only cooling the gaseous refrigerant, if the refrigeration circuit 2 is operated in a transcritical mode.
- the refrigerant circulating in the refrigeration circuit can be of any conventional kind, however, it is particularly suitable for transcritical operation. Thus, also CO2 can be used as refrigerant.
- All of the compressors of the multi-compressor unit namely the VSD-controlled compressor 4, the first constant speed compressor 6 and the second constant speed compressor 8 comprise an oil sump, and an oil balance line 30 attaches to the same positions of height of the oil sump of the VSD-controlled compressor 4 and the constant speed compressor 6 and connects the oil sumps of these compressors 4 and 6.
- This oil balance line 30 also extends to the second constant speed compressor 8, and is connected to the oil sump level of the second constant speed compressor 8 attaching to the same position of height of its oil sump level.
- This oil balance line to the second constant speed compressor 8 has the reference numeral 34.
- the oil sump levels are provided with a sight glass for allowing monitoring of the oil sump levels within the oil sump of the compressors 4, 6 and 8.
- a solenoid valve 32 is provided that allows oil flow in either direction and that is capable for controlling the oil distribution between the oil sumps of the VSD-controlled compressor 4 on the one hand and the constant speed compressor 6 and 8 on the other hand during operation of the compressors 4, 6 and 8 of the multi- compressor unit.
- the oil flow direction within the oil balance line 30 is depicted by an arrow having the reference numeral 36.
- the oil sump levels of the compressors 4, 6 and 8 are monitored and the solenoid valve 32 is closed if the oil sump level of one of the compressors 4, 6 and 8 exceeds a predetermined upper threshold value or falls below a predetermined lower threshold value, thereby blocking an undesired oil flow between the speed controlled compressor 4 and the constant speed compressors 6 and 8.
- the oil sump levels of the compressors 4, 6 and 8 are monitored and the solenoid valve 32 is closed if the oil sump levels difference between the speed controlled compressor 4 and one of the further constant speed compressors 6 and 8 exceeds a predetermined upper threshold value, thereby blocking an undesired oil flow between the speed controlled compressor 4 and the constant speed compressors 6 and 8.
- the pressure difference between the speed controlled compressor 4 and the constant speed compressors 6 and 8 is monitored and the solenoid valve 32 is closed if this pressure difference exceeds a predetermined threshold value, thereby blocking an undesired oil flow between the speed controlled compressor 4 and the constant speed compressors 6 and 8.
- the rotational speed of the speed controlled compressor 4 is monitored and the solenoid valve 32 is closed if the rotational speed of the speed controlled compressor 4 exceeds a predetermined upper threshold value or falls below a predetermined lower threshold value, thereby blocking an undesired oil flow between the speed controlled compressor 4 and the constant speed compressors 6 and 8.
- control features can employ means for sensing the required values (not shown in the Figure), for example means for monitoring the oil sump levels, means for measuring a pressure difference or means for measuring the rotational speed, and the solenoid valve is controlled so as to close if the sensed values are no more in an acceptable range and/or so as to close if the sensed values are in an acceptable range again.
- the rotational speed is used for as control feature, it is not necessary to provide a certain device. It is possible to just refer to the known frequency controlled by the VSD. Since every other compressor runs at the same, constant and of course known frequency of the local power supply and the frequency of the VSD output is given the difference can be used to calculate the difference of rotational speed.
- the solenoid valve 32 can be closed and opened up at predetermined intervals for blocking, and respectively, allowing oil flow between the speed controlled compressor 4 and the constant speed compressors 6 and 8.
- the extent of the oil distribution between the speed controlled compressor 4 and the constant speed compressors 6 and 8 can be limited in terms of time, and the opening and closing intervals can be selected according to the specification and the expected load or performance of the refrigerating circuit.
- the solenoid valve closes and avoids an oil distribution between the speed controlled compressor and the other constant speed compressors.
- a unit controller (not shown in the Figure) can be applied that controls the condenser/gas cooler 12, the compressors 4, 6 and 8 and the solenoid valve 32.
- the control of this unit controller can be carried out by a control algorithm for the solenoid valve 32 being integrated into the unit controller or by a separate impulse generator.
- the oil distribution between the compressors can be effected during normal operation of the compressors of the multi-compressor unit. It is neither necessary to switch off a compressor in order to run an oil distribution program nor is it necessary to provide an additional oil separator.
- the oil distribution between the oil sumps of the compressors can be controlled during operation of all the compressors running which avoids switching off one or the other compressor for a certain time interval and which significantly improves the efficiency of the refrigerating circuit.
- the oil levels in the oil sumps of all the compressors can reliably be kept in an acceptable range.
- the oil balance line attaches to positions of height at the oil sumps of the compressors that corresponds to the necessary oil level of the compressors in operation.
- the oil balance line can attach to other positions of height within an acceptable oil level range between a position of minimum required oil level and a position of maximum required oil level or even lower.
- the oil balance line always attaches to substantially the same positions of height of the oil sumps present in the multi-compressor unit, wherein a variation of a few millimeters is acceptable.
- the suction pressure of the compressors of the multi-compressor unit lies at substantially the same suction pressure level for all compressors.
- the refrigerating circuit according to exemplary embodiments, as described above, does not use a pressure difference for regulating the oil level, and the equipment necessary for such oil regulation due to pressure differences can be avoided, which saves further costs and effort.
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)
- Air Conditioning Control Device (AREA)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09776516.8A EP2417405B1 (de) | 2009-04-06 | 2009-04-06 | Kältekreislauf und verfahren zur steuerung der ölverteilung darin |
PCT/EP2009/002529 WO2010115435A1 (en) | 2009-04-06 | 2009-04-06 | Refrigerating circuit and method for controlling the oil distribution within the same |
CN200980158537.8A CN102388278B (zh) | 2009-04-06 | 2009-04-06 | 制冷回路以及用于控制制冷回路中的油分布的方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/EP2009/002529 WO2010115435A1 (en) | 2009-04-06 | 2009-04-06 | Refrigerating circuit and method for controlling the oil distribution within the same |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2010115435A1 true WO2010115435A1 (en) | 2010-10-14 |
Family
ID=41698196
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2009/002529 WO2010115435A1 (en) | 2009-04-06 | 2009-04-06 | Refrigerating circuit and method for controlling the oil distribution within the same |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2417405B1 (de) |
CN (1) | CN102388278B (de) |
WO (1) | WO2010115435A1 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017100314A1 (en) * | 2015-12-08 | 2017-06-15 | Bitzer Kuehlmaschinenbau Gmbh | Cascading oil distribution system |
WO2017127241A1 (en) * | 2016-01-22 | 2017-07-27 | Bitzer Kuehlmaschinenbau Gmbh | Oil distribution in multiple-compressor systems utilizing variable speed |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104748440B (zh) * | 2015-03-31 | 2017-06-27 | 广东美的制冷设备有限公司 | 空调系统及空调系统的控制方法 |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3633377A (en) * | 1969-04-11 | 1972-01-11 | Lester K Quick | Refrigeration system oil separator |
JPS6334451A (ja) * | 1986-07-28 | 1988-02-15 | 株式会社日立製作所 | マルチ冷凍機 |
JPH01193088A (ja) * | 1988-01-29 | 1989-08-03 | Toshiba Corp | 空気調和機 |
EP0403239A2 (de) * | 1989-06-14 | 1990-12-19 | Hitachi, Ltd. | Verdichteranlage mit steuerbarer Leistung |
JPH0480555A (ja) * | 1990-07-19 | 1992-03-13 | Sanyo Electric Co Ltd | 冷凍装置 |
JPH0527560U (ja) * | 1991-09-20 | 1993-04-09 | 三菱重工業株式会社 | 冷凍装置 |
US5634345A (en) * | 1995-06-06 | 1997-06-03 | Alsenz; Richard H. | Oil monitoring system |
JP2000337726A (ja) * | 1999-05-24 | 2000-12-08 | Sanyo Electric Co Ltd | 空気調和装置 |
EP1120611A1 (de) * | 1999-07-21 | 2001-08-01 | Daikin Industries, Ltd. | Kühlvorrichtung |
EP1614983A2 (de) * | 2004-06-29 | 2006-01-11 | Samsung Electronics Co., Ltd. | Klimaanlage |
EP1677057A2 (de) * | 2004-12-28 | 2006-07-05 | Samsung Electronics Co., Ltd. | Wärmepumpe mit Kompressorölverteilung |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN2665406Y (zh) * | 2003-11-08 | 2004-12-22 | 海尔集团公司 | 可实现定时均油处理的空调器 |
JP2005291885A (ja) * | 2004-03-31 | 2005-10-20 | Nec Corp | ナビゲーション機能付き携帯通信端末 |
CN1940409A (zh) * | 2005-09-29 | 2007-04-04 | 海尔集团公司 | 多联空调油平衡的控制方法 |
-
2009
- 2009-04-06 EP EP09776516.8A patent/EP2417405B1/de active Active
- 2009-04-06 CN CN200980158537.8A patent/CN102388278B/zh not_active Expired - Fee Related
- 2009-04-06 WO PCT/EP2009/002529 patent/WO2010115435A1/en active Application Filing
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3633377A (en) * | 1969-04-11 | 1972-01-11 | Lester K Quick | Refrigeration system oil separator |
JPS6334451A (ja) * | 1986-07-28 | 1988-02-15 | 株式会社日立製作所 | マルチ冷凍機 |
JPH01193088A (ja) * | 1988-01-29 | 1989-08-03 | Toshiba Corp | 空気調和機 |
EP0403239A2 (de) * | 1989-06-14 | 1990-12-19 | Hitachi, Ltd. | Verdichteranlage mit steuerbarer Leistung |
JPH0480555A (ja) * | 1990-07-19 | 1992-03-13 | Sanyo Electric Co Ltd | 冷凍装置 |
JPH0527560U (ja) * | 1991-09-20 | 1993-04-09 | 三菱重工業株式会社 | 冷凍装置 |
US5634345A (en) * | 1995-06-06 | 1997-06-03 | Alsenz; Richard H. | Oil monitoring system |
JP2000337726A (ja) * | 1999-05-24 | 2000-12-08 | Sanyo Electric Co Ltd | 空気調和装置 |
EP1120611A1 (de) * | 1999-07-21 | 2001-08-01 | Daikin Industries, Ltd. | Kühlvorrichtung |
EP1614983A2 (de) * | 2004-06-29 | 2006-01-11 | Samsung Electronics Co., Ltd. | Klimaanlage |
EP1677057A2 (de) * | 2004-12-28 | 2006-07-05 | Samsung Electronics Co., Ltd. | Wärmepumpe mit Kompressorölverteilung |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017100314A1 (en) * | 2015-12-08 | 2017-06-15 | Bitzer Kuehlmaschinenbau Gmbh | Cascading oil distribution system |
US9939179B2 (en) | 2015-12-08 | 2018-04-10 | Bitzer Kuehlmaschinenbau Gmbh | Cascading oil distribution system |
WO2017127241A1 (en) * | 2016-01-22 | 2017-07-27 | Bitzer Kuehlmaschinenbau Gmbh | Oil distribution in multiple-compressor systems utilizing variable speed |
CN108474596A (zh) * | 2016-01-22 | 2018-08-31 | 比泽尔制冷设备有限公司 | 利用可变的速度在多压缩机系统中进行油分配 |
US10760831B2 (en) | 2016-01-22 | 2020-09-01 | Bitzer Kuehlmaschinenbau Gmbh | Oil distribution in multiple-compressor systems utilizing variable speed |
Also Published As
Publication number | Publication date |
---|---|
CN102388278B (zh) | 2014-11-19 |
CN102388278A (zh) | 2012-03-21 |
EP2417405A1 (de) | 2012-02-15 |
EP2417405B1 (de) | 2020-03-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101815579B1 (ko) | 냉장고 및 그 운전방법 | |
EP3205955A1 (de) | Klimaanlage | |
US9488396B2 (en) | Air-conditioning apparatus | |
KR100516381B1 (ko) | 냉동장치 | |
EP3205954B1 (de) | Kältekreislaufvorrichtung | |
US9551351B2 (en) | Compression device and a thermodynamic system comprising such a compression device | |
WO2010013392A1 (ja) | 冷凍装置 | |
CN106225278B (zh) | 制冷循环系统 | |
WO2007139010A1 (ja) | 冷凍装置 | |
KR101336564B1 (ko) | 열원 유닛 | |
JP2010175190A (ja) | 空気調和機 | |
US5222370A (en) | Automatic chiller stopping sequence | |
US20220082308A1 (en) | Refrigeration apparatus | |
EP1769414A1 (de) | Verbesserte schmiermittel-rückführungsverfahren im kühlzyklus | |
JP2016173202A (ja) | ヒートポンプ | |
EP2417405B1 (de) | Kältekreislauf und verfahren zur steuerung der ölverteilung darin | |
EP2182305A1 (de) | Methode zur Regelung der Verteilung des Schmieröls in einer Verdichtereinheit und Verdichtereinheit | |
JP2010054193A (ja) | 冷凍装置 | |
US9163862B2 (en) | Receiver fill valve and control method | |
JP2018071907A (ja) | 冷凍装置、冷凍システム | |
US10816251B2 (en) | Heat pump | |
EP3537061A1 (de) | Ölausgleichssteuerungsvorrichtung, kühlmittelkreislaufsystem und ölausgleichsverfahren | |
JP2009264612A (ja) | 冷凍装置 | |
JP2002039602A (ja) | 空気調和機 | |
GB2559899A (en) | Air-conditioning device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980158537.8 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09776516 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009776516 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |