• Journal of Mechanical Science and Technology
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• 제18권9호
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• pp.1537-1548
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• 2004

This paper presents a novel diagnostic technique for monitoring the system conditions and detecting failure modes and precursors based on wavelet-packet analysis of external noise/vibration measurements. The capability is based on extracting relevant features of noise/vibration data that best discriminate systems with different noise/vibration signatures by analyzing external measurements of noise/vibration in the time-frequency domain. By virtue of their localized nature both in time and frequency, the identified features help to reveal faults at the level of components in a mechanical system in addition to the existence of certain faults. A prima-facie case is made via application of the proposed approach to fault detection in scroll and rotary compressors, although the methods and algorithms are very general in nature. The proposed technique has successfully identified the existence of specific faults in the scroll and rotary compressors. In addition, its capability of tracking the severity of specific faults in the rotary compressors indicates that the technique has a potential to be used as a prognostic tool.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.718-723
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• 2016

중형 차량용 에어컨에 사용되는 스크롤 압축기는 토크변동이 적고 에너지 효율이 높으며, 소음이 적어 적용이 확대되어 가고 있다. 또한 경량화에 따라 압축기를 구성하는 주요부품이 스틸에서 알루미늄으로 변경하는 등 소재에 대한 연구가 활발히 이루어지고 있다. 또한 스크롤 압축기는 고정 스크롤과 선회 스크롤의 인벌루트 랩의 가공 정밀도가 $10{\mu}m$ 이하로 정밀도가 높은 전용장비와 전용 툴은 물론 숙련된 가공기술이 요구되므로 가공 품질을 확인하기 위하여 표면조도와 윤곽도를 측정하였으며, 알루미늄을 모재로하여 양극 산화 처리하여 사용되고 있는 선회스크롤의 경도를 향상시키기 위한 방법의 일환으로 봉공처리를 수행에 따른 특성들을 살펴보았다. 알루미늄 소재는 Al-Mg-Cu계 합금으로 미량의 Ni, Fe, Zn 이 부가된 것으로 나타났으며, 표면조도는 $3{\mu}m$이하로 가공 정밀도 기준 $10{\mu}m$를 만족하였다. 또한 양극산화 후 나노다이아몬드, CNT로 봉공처리 한 경우 경도는 450 이상으로 수봉공처리의 경우 보다 50% 이상 경도가 향상됨을 알 수 있었으며, 봉공재로 사용하기 위한 소재로서 탄소나노튜브나 나노다이아몬드는 큰 차이를 보이지 않았다.

• 한국유체기계학회 논문집
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• 제19권6호
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• pp.50-54
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• 2016

The performance of a scroll expander is the most important factor for the efficiency of small scale Organic Rankine cycle waste heat power generation systems. In this research, a scroll compressor was purchased and operated in reverse to function as a scroll expander. With air as a working fluid, a series of performance test were conducted on this expander by varying the inlet and outlet pressure. Secondly, We have tested through 2000 to 3500 rpm rotational speed to find the maximum power and efficiency of the expander. And last, It was observed in the initial experiments that the design of the expander's orbiting scroll wrap partially blocked the fluid intake which may have caused unnecessary flow resistance. To verify this theory, a small part of the scroll wrap was removed and the performance test was redone. It was observed that the lower back pressure assure the higher efficiency and power of expander and the rotational speed that shows maximum adiabetic efficiency of scroll expander is 69% at 2500 rpm. And by modified wrap of the scroll, we could get volume flow rate for 13% to 19% and power for 5% to 18% increased. But the maximum efficiency of the modified scroll was decreased 8%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.169-173
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• 2008

Stirling engine is a promising heat engine with a high efficiency, muti-fuel capability, low emission, quiet operation, very low maintenance and long life. As one of the promising applications, solar power system based on the Stirling dish, providing net solar-to-electric conversion efficiencies reaching 30%, can operate as stand-alone units in remote locations or can be linked together in groups to provide utility-scale power. This paper introduced a new Scroll-type Stirling engine, being developed for solar power, superior to conventional Stirling engines. The Scroll-type Stirling engine is characterized as traits of continuous and wholly separated compression and expansion; one-way flow system; direct cooling and heating the fluid in the working spaces through the extensive inner surfaces of scroll wraps. All theses traits contribute to achieving thermodynamic cycle closer to the ideal Stirling cycle (exactly speaking, Ericsson cycle).

• 융복합기술연구소 논문집
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• 제4권1호
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• pp.29-32
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• 2014

최근 유가상승 및 환경오염으로 인하여 자동차 연비 개선에 대한 관심이 날로 증가하고 있어 자동차 제조사들은 다양한 접근방법을 통해 경량화를 달성하고자 하고 있다. 경량화 방법으로는 경량재료의 적용, 고강도 소재를 이용한 부품소형화, 조립식 파트의 일체형 모듈화 등이 있으며, 본 연구에서는 경량구조재료인 마그네슘 합금을 자동차용 스크롤 압축기에 적용하기 위하여 기존 알루미늄 합금부품과의 열팽창 및 열변형의 비교를 통해 마그네슘 합금 적용한 스크롤 부품의 설계시 고려되어야 할 요소들을 분석 및 제시하고자 한다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 하계학술발표대회
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• pp.49-49
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• 2005

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 하계학술발표대회 논문집
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• pp.3-3
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• 2007

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.194-202
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• 2008

In this study, we investigated the tribology behaviour of two different bearing materials. One of these alloys content is Cu(90)-Sn(10) alloy and is widely used in the automotive industry.The other is Al alloy. This bearing content is Al-Sn-Si-Cu. Therefore, it is required to study on the lublicating characteristics of bearing according to different materials. In this study, compressor bearings made by respectively "PTFE solid lubricant" and "AI alloy with superior load carrying capacity, rubbing and impact endurance", have gone through journal bearing test. Lubrication and abrasion characteristics are evaluated by analyzing the material characteristics of a scroll compressor bearing bush. The AI alloy bearing showed the most excellent lubrication and abrasion characteristics than Cu-Sn alloy under high load condition.

• 에너지공학
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• 제20권4호
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• pp.286-291
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• 2011

하이브리드 자동차는 전기방식 회생제동을 이용하여 연비가 우수하다. 본 논문에서는 새로운 공압식 회생제동 장치를 소개하였다. 공압식 회생제동장치는 압축과 팽창기능을 동시에 가지는 스크롤 기구를 이용한다. 차량 감속시에는 스크롤 기기는 압축기로 작동되면서 대기중의 공기를 압축하여 압축탱크에 저장한 후 차량 가속시에는 스크롤기구가 팽창기로 작동되면서 탱크에 저장된 압축공기가 차량 운동에너지로 활용된다. 회생제동장치를 사용함으로써 개선되는 연비를 분석하기 위해, CVS-75 모드 주행조건에서 시뮬레이션을 수행하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.590-595
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• 2006

This paper presents the friction and anti-wear characteristics of nano-oil with a mixture of a refrigerant oil and carbon nano-particles in the thrust slide-bearing of scroll compressors. Frictional loss in the thrust slide-bearing occupies a large part of total mechanical loss in scroll compressors. The characteristics of friction and anti-wear using nano-oil are evaluated using the thrust bearing tester for measuring friction surface temperature and the coefficient of friction at the thrust slide-bearing as a function of normal loads up to 4,000 N and orbiting speed up to 3,200 rpm. It is found that the coefficient of friction increases with decreasing orbiting speed and normal force. The friction coefficient of carbon nano-oil is 0.015, while that of pure oil is 0.023 under the conditions of refrigerant gas R-22 at the pressure of 5 bars. It is believed that carbon nano-particles can be coated on the friction surfaces and the interaction of nano-particles between surfaces can be improved the lubrication in the friction surfaces. Carbon nano-oil enhances the characteristics of the anti-wear and friction at the thrust slide-bearing of scroll compressors.