• 제목/요약/키워드: compressor oil

검색결과 177건 처리시간 0.024초

이단 압축기의 동력학적 설계 및 운전 특성에 관한 연구 (Design and Operation Characteristics of a Two-Stage Compressor)

  • 이용복;김태호;김창호;이남수;최동훈
    • 한국유체기계학회 논문집
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    • 제5권1호
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    • pp.55-61
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    • 2002
  • The feasibility of an oil-free, motor-driven, two-stage centrifugal compressor supported by air bump bearings is investigated. This centrifugal compressor is driven by a 75 kW motor at an operating speed of 39,000 RPM, and a pressure ratio of the compressor is set up to 4. The analysis is performed by using bearing equilibrium position, heaving stillness, Campbell diagram, unbalance response, and stability. It is demonstrated in this paper that air bump bearings can be adopted well to an oil-free, motor-driven, centrifugal compressor. Specially, Cu-coated bump bearings have enough damping force to reduce a synchronous unbalance for rigid modes of the two-stage compressor. Futhermore, this concept may be applied to the flexible rotor system such as high speed turbomachinery with a super critical speed.

차량용 공기현가장치의 무급유 공기압축기 성능해석 (Performance analysis of oil free air compressor for automotive electronic air suspension system)

  • 심재휘;김호영;이용호;김현진
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.572-577
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    • 2006
  • Numerical simulation has been made on the performance of an oil free air compressor for automotive electronic air suspension system. Calculation results on the flow rate at various air supply pressures were reasonably well compared to the experimental data. With the aid of the computer simulation program, parametric study on the compressor design parameters has also been carried out for the compressor performance improvement: Increase in the discharge port diameter or discharge valve stiffness was found to be effective to increase the flow rate per unit compressor input for the present compressor model.

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무급유식 공기압축기 구동을 위한 영구자석 동기 모터의 센서리스 속도제어 (Sensor-less Speed Control of PMSM for Driving Oil-free Air Compressor)

  • 김민호;양오;김윤현
    • 반도체디스플레이기술학회지
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    • 제14권3호
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    • pp.45-50
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    • 2015
  • This paper suggests the sensor-less speed control of PMSM (Permanent Magnet Synchronous Motor) without the position sensor of oil-free air compressor. It estimated d and q axis back electro motive force using Back-EMF (Electro motive Force) observer to control sensor-less speed of PMSM. Also it used the method that tracks the information of rotor position and speed using PLL (Phase Locked Loop) based on estimated d and q axis Back-EMF. The sensor-less speed control of PMSM for oil air compressor application is carried out with the introduced rotor position and speed tracking method. In this paper, the experimental characterization of the sensor-less drive is provided to verify the accuracy of the estimated position and the performance of sensor-less control is analyzed by results obtained from the experiment. Moreover, the potential of PMSM sensor-less drive in industrial application such as compressor drive is also examined.

공기 포일 베어링으로 지지되는 터보 압축기의 공력 불안정성이 로터에 미치는 진동 영향 (Rotordynamci Effects Due to Aerodynamic Instability in a Turbo-compressor with Air Foil Bearings)

  • 김태호;이용복;김창호;김광호;이남수
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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    • pp.191-198
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    • 2002
  • Oil-free turbo-compressor supported by compliant foil bearings which remove oil-contamination by elimination of the conventional ball bearing and oil lubrication systems is presented. Turbo-compressor makes two individual air compression with two impellers at operating speed, 39,000rpm. In this study, the rotordynamic effects caused by aerodynamic instability were investigated with variable mass flow rate. Correlation between frequencies of pressure fluctuation in two diffusers and those of excitation forces on rotor were clearly developed in aerodynamic unsteady region. Thus, these results show that it is beneficial to design high speed rotating turbomachinery considering coupling effect between aerodynamic instability and rotordynamic force.

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공기 포일 베어링으로 지지되는 터보 압축기의 공력 불안정성이 로터에 미치는 진동 영향 (Rotordynamic Effects Due to Aerodynamic Instability in a Turbo-compressor with Air Foil Bearings)

  • 김태호;이용복;김창호;이남수;김광호;신유환
    • 한국유체기계학회 논문집
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    • 제6권2호
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    • pp.62-69
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    • 2003
  • An oil-free turbo-compressor supported by compliant foil bearings which remove oil-contamination by elimination of a conventional ball bearing and oil lubrication systems is presented. Turbo-compressor makes two individual air compressions with two impellers at a operating speed of 39,000 rpm. In this study, the rotordynamic effects caused by aerodynamic instability were investigated with variable mass flow rates. Correlations between frequencies of pressure fluctuation in two diffusers and those of excitation forces on rotor were clearly observed in an aerodynamic unsteady region. Thus, these results show that it is beneficial to design high-speed rotating turbomachinery by considering coupling effect between aerodynamic instability and rotordynamic force.

접촉압력을 고려한 R-134a용 냉도기유의 윤활성 평가 연구

  • 나병철;전경진;한동철
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1997년도 제26회 추계학술대회
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    • pp.145-151
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    • 1997
  • PAG(Polyalkylene Glycol) and esters are tested with HFC-134a as a refrigeration oil. This investigation enhances the testing method by taking the compressor's environment into account. A testing environment charged with refrigerant gas more closely simulates the conditions of a compressor. The friction coetTicient of the PAG/HFC-134a system is similar to that of the mineral oil/CFC-12 system at operating conditions. Ester oils are preferable at the start & stop condition in the lubricity aspect. PAG shows good lubricity in conditions of extreme contact pressure. Consequently, this test provides reliable results on compressor lubricity of refrigeration oils with HFC-134a. It suggests a methodological way for the proper selection of refrigeration oils that may improve the durability and performance of a compressor.

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저진동을 위한 터보형 공기압축기의 설계 (TURBO TYPE AIR COMPRESSOR DESIGN FOR LOW VIBRATION LEVEL)

  • 김명국;정용수;박노길
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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    • pp.159-165
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    • 1998
  • Bearing design of turbo type geared centrifugal air compressor for low vibration level has been studied. The Transfer Matrix Method was used in this paper to analyze the air-compressor consisting of impellers, multi-stage geared rotors, and oil-film hearings. We have to consider this air-compressor as multi-geared rotating system, because characteristics of rotor-bearing system are different from conventional characteristics of non-rotating system. From the view point of Rotordynamics, the stiffness and damping coefficient of oil-film bearing in case of compressor system are more sensitive than other design parameters such as shaft length, shaft diameter and the weight of impellers, etc. Therefore, the stiffness and damping coefficients on each bearing were considered as design parameters. As the result of this study, turbo type air compressor with low vibration level can be achieved.

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이단 압축기의 동력학적 설계 및 운전 특성에 관한 연구 (Design and Operation Characteristics of A Two-Stage Compressor)

  • 이용복;이남수;김태호;김창호;최동훈
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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    • pp.469-474
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    • 2001
  • The feasibility of a oil-free motor-driven two-stage centrifugal compressor supported by air bump bearings is investigated. This centrifugal compressor is driven by 75kW motor at an operating speed of 39,000RPM md a pressure ratio of the compressor is up to 4. The analysis is performed, based upon bearing equilibrium position, bearing stiffness, Campbell diagram, unbalance response and stability. It is demonstrated in this paper that air bump bearings can be adopted well to a oil-free motor-driven centrifugal compressor.

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공조용 압축기 축 거동 측정용 베어링 내장형 센서 (The built-in sensor bearing to measure shaft behavior of compressor for air-conditioning)

  • 김지운;안형준;김지영;한동철;윤정호;황인수
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제34회 추계학술대회 개최
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    • pp.230-236
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    • 2001
  • We developed a built-in sensor bearing to measure the rotor motion of a rolling piston type compressor for the air conditioner. Because of needs for the high efficiency and long life span of compressor, and the usage of alternative refrigerants, the operating condition of the compressor becomes more severe. The accurate measurement of the rotor motion of the compressor can contribute greatly to the design and analysis of the hydrodynamic bearing. However, it is difficult to measure accurately the shaft behavior of small compressor because of the small space for the sensor mount, high temperature and pressure of compressor, oil mixed with refrigerant, and electromagnetic noise of the motor. To overcome these difficulties, we develop the cylindrical capacitive sensor that is built in the hydrodynamic bearing and calibrate the built-in sensor bearing indirectly through measuring the oil relative permittivity. We measured the rotor motion as well as suction and discharge pressures in various conditions. The several experimental results show that the developed built-in sensor bearing can measure the rotor motion not only in steady state but also in transient state.

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왕복동식 압축기의 저널 베어링 오일 패스 설계를 위한 연구 (A Study on Oil Path Design in the Journal Bearing of a Reciprocating Compressor)

  • 조인성;정재연
    • 한국정밀공학회지
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    • 제30권8호
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    • pp.839-846
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    • 2013
  • Because the performance of a reciprocating compressor in refrigeration and air-conditioning systems is influenced by the lubrication characteristics of sliding components, the lubrication characteristics between the crankshaft and journal bearing have to be researched for the design and the performance improvement of reciprocating compressors. Thus, the proper supply of lubricant for a lubrication between the crankshaft and journal bearing is essential, and an oil path for lubricant supply is installed in the shaft or bearing. However, in order to guarantee the lubrication performance of the journal bearing, it is necessary to design the position of the oil path. Therefore, it is studied to find the optimum position of the oil path by the analysis of the pressure distribution in the journal bearing. The results show that the position of the oil path is significantly influenced by the pressure distribution of the oil film in the journal bearing.