• 제목/요약/키워드: engine-oil

검색결과 870건 처리시간 0.031초

극지해역 운용 해양작업지원선(PSV)의 선형설계와 빙 저항추진 성능 연구 (A Study on the Hull Form Design and Ice Resistance & Propulsion Performance of a Platform Support Vessel (PSV) Operated in the Arctic Ocean)

  • 염종길;강국진;장진호;정성엽
    • 대한조선학회논문집
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    • 제55권6호
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    • pp.497-504
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    • 2018
  • Platform Support Vessels operated in the Arctic Ocean support diverse operations of offshore plant in the sea, and the PSV is also needed to support works to exploit the oil and gas in the Arctic Ocean. Both of the ice breaking and the open sea performance have been considered together to secure the enhanced operational performance at the harsh environment in the Arctic Ocean and the open sea as well. In this study, One of the design requirements of a PSV is to guarantee continuous icebreaking performance with 3 knots at 1 m thickness of level ice, where the design draft is 7.5m and the engine power is 13 MW. Three hull forms were designed, and the ice resistance based on empirical formulas was estimated to select the initial hull form having an outstanding performance. The full scale performance of the designed hull forms was predicted by the ice model test conducted in the ice model basin of Korea Research Institute of Ships & Ocean Engineering(KRISO). The analysed results show that the selected hull form satisfies the above design requirement.

Study on Equivalent Consumption Minimization Strategy Application in PTI-PTO Mode of Diesel-Electric Hybrid Propulsion System for Ships

  • Lee, Dae-Hong;Kim, Jong-Su;Yoon, Kyoung-Kuk;Hur, Jae-Jung
    • 해양환경안전학회지
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    • 제28권3호
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    • pp.451-458
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    • 2022
  • In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

차량기술, 연료 유종 및 시험모드 특성에 따른 온실가스의 배출특성 연구 (A study on the emission characteristics of greenhouse gases according to the vehicle technology, fuel oil type and test mode)

  • 이정천;이민호;김기호;박언영
    • 한국응용과학기술학회지
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    • 제34권4호
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    • pp.962-973
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    • 2017
  • 대기오염에 대한 관심은 국내 외에서 점진적으로 상승하고 있으며, 자동차 및 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 이용하여 새로운 엔진 설계, 혁신적인 후처리 시스템 등의 연구를 통하여 차량 배기가스 및 온실가스를 감소시키고자 노력하고 있다. 이에 본 연구에서는 각기 다른 차량기술이 적용된 휘발유, 경유, LPG를 연료로 사용하는 7대의 차량을 대상으로 국내 외에서 법적시험모드로 사용되고 있는 도심모드, 고속모드, 급가 감속, 에어컨사용 및 겨울철 특성을 반영한 저온모드에서 온실가스의 배출특성을 확인하고자 하였다. 사용연료에 관계없이 대부분의 온실가스는 저온인 Cold FTP-75 모드에서 가장 안 좋은 결과가 나타나는 경향을 가지고 있다. 각 차량별 온실가스 증가 요인으로는 가솔린 차량인 A차량(2.0 MPI)과 B차량(2.4 GDI)에서는 최고속 및 급가 감속, 에어컨 사용, 저온 조건의 순인데 비해 E차량(1.6 T-GDI)은 에어컨 사용, 최고속 및 급가 감속, 저온 조건의 순이다. G차량(LPLi)은 에어컨 사용, 저온, 최고속 및 급가 감속 조건의 순으로 가솔린 차량과 다른 특성을 가지고 있다. 경유 차량에 있어서는 A차량(2.0 w/o DPF)과 B차량(2.2 w/ DPF)은 최고속 및 급가 감속, 에어컨 사용, 저온 조건의 순이었고, F차량(1.6 w/ DPF)은 저온, 에어컨 사용, 최고속 및 급가 감속 조건의 순으로 확인되었다. 따라서, 각 연료별로 배출가스 저감 기술을 다르게 적용하여야 효과적인 방법이라고 할 수 있겠다.

장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구 (A Study on the Thermal Stability of Long-Term Fuel Storage and Lifetime Estimation of Rubber O-ring in Contacted with Fuel)

  • 정근우;홍진숙;김영운;한정식;정병훈;권태수;서동욱;성민준;권영일
    • Tribology and Lubricants
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    • 제34권5호
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    • pp.197-207
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    • 2018
  • Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.

3 방향 절환밸브의 공동현상 저감을 위한 형상최적화 (Shape Optimization of Three-Way Reversing Valve for Cavitation Reduction)

  • 이명곤;임채석;한승호
    • 대한기계학회논문집A
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    • 제39권11호
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    • pp.1123-1129
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    • 2015
  • 자동차부품 세척장비는 엔진과 변속기 블록 등의 가공과정에서 잔류하는 기름때를 제거하며, 잦은 수류방향 전환과 고압수의 분사를 위해 한 쌍의 2 방향 밸브를 사용한다. 그러나 정교한 밸브제어장치 없이 2 방향 밸브를 사용하는 경우 급격한 수류방향 전환에 따른 맥동현상이 발생하여 사용에 어려움이 따른다. 대안으로 하나의 3 방향 절환밸브를 사용하는 방법은 정교한 제어장치 없이도 정확한 수류방향 절환이 원활히 이루어져 이러한 문제점을 해결할 수 있다. 그러나 복잡한 유로 및 바텀플러그 형상으로 인해 유속변화가 심하게 발생하여 공동현상이 나타날 수 있다. 본 연구에서는 3 방향 절환밸브 내의 유동특성을 해석적으로 평가하였으며, 바텀플러그 하부에서 나타나는 공동현상을 공동화지표와 POC(Percent of cavitation)를 도입하여 정량화하였다. 공동현상의 저감을 위해 바텀플러그 형상을 매개변수화하고, 해석의 수렴성 개선과 해석시간을 단축시킬 수 있는 단순 유한요소모델을 이용하여 유동해석을 통한 형상최적설계를 실시하였다. 완전요인배치법을 통한 실험계획법과 인공신경망 기반 반응표면모델을 적용하여 공동현상이 발생하지 않는 POC 가 30% 미만인 바텀플러그의 형상을 제시하였다. 얻어진 최적해는 POC 27%에 대하여 바텀플러그의 허리길이와 꼬리길이가 각각 6.42mm 및 6.96mm 이다.

충남지역 해양산업 구조 분석 연구 (A Study on Analysis of Maritime Industry Structure on Chungnam Province)

  • 김운수;최경훈;김화영
    • 한국항만경제학회지
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    • 제34권2호
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    • pp.1-16
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    • 2018
  • 해양산업은 새로운 부가가치산업 및 신성장동력 산업으로 인식되고 있다. 특히 항만을 중심으로 클러스터를 조성하여 고부가가치를 창출하고 있다. 해외 선진항만들도 앞 다투어 클러스터를 조성하여 수익창출과 경쟁력 강화에 나서고 있다. 우리나라도 2015년 해양산업클러스터 조성과 육성에 관한 법률을 제정하였다. 따라서 각 지역별로 어떤 해양산업이 비교우위에 있는지 파악하는 것은 해양산업클러스터를 통한 집적화 전략을 수립하는데 매우 중요하다. 따라서 본 연구에서는 유류를 중심으로 한 원자재 처리와 함께 컨테이너 처리, 중국과 카페리 항로 개설을 앞두고 있는 충남지역을 대상으로 해양산업 구조를 분석하였다. 먼저 해양산업 분류에 대한 기존 문헌분석을 실시하여 해운 물류업, 조선업, 수산업, 해양관광업, 기타업 5개의 대분류와 21개 중분류, 84개 소분류로 해양산업을 재분류하였다. 재분류한 해양산업을 기준으로 입지계수와 변이할당분석 기법을 활용하여 충남의 해양산업 구조를 분석하였다. 충남지역 해양산업 구조 분석결과, 입지계수 분석에 있어서 수산업이 1.718로 가장 높게 나타났고, 해양관광(1.092), 조선업(0.823), 해운 물류업(0.789)순으로 나타났다. 그리고 변이할당분석을 통해 충남지역 해양산업의 총 성장효과는 36,315명으로 나타났고 국가성장효과를 제외한 순성장효과는 21,321명으로 산정되었다. 이러한 결과를 바탕으로 충남지역 해양산업 중 비교우위, 비교열위에 있는 산업을 분류하였다. 이 연구결과는 향후 충남지역 해양산업클러스터 구축 시 전략수립에 기초자료로 활용할 수 있을 것이다.

태양광을 이용한 자율주행 자동차의 능동적 자가 충전 및 운행 제안 (Proposal on Active Self Charging and Operation of Autonomous Vehicle Using Solar Energy)

  • 허현우
    • 한국콘텐츠학회논문지
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    • 제22권9호
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    • pp.85-94
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    • 2022
  • 현대 시대는 환경 및 에너지 문제로 인해 자동차를 친환경 에너지로 대체하는 움직임이 생겨났다. 내연기관 자동차는 석유 에너지를 사용하여 미세먼지, 오존과 같은 환경 문제로 지구 오염에 영향을 주는 요인 중 하나이다. 또한 자동차의 에너지원으로 사용되는 자원이 고갈되고 있다. 이 한정된 에너지를 대체함으로 문제 해결방법을 찾는다. 문제를 해결하기 위해 대체 에너지로써 친환경 에너지를 사용하는 방법 및 전기 에너지를 사용하는 방법 등을 해결책으로 내놓고 있다. 본 논문은 친환경 에너지 중 태양광 에너지를 이용한 자율주행 자동차의 자가 충전 및 운행을 제안하여 환경오염 및 자동차의 대체 에너지로의 사용 가능성을 연구하였다. 발표된 문헌 자료들과 국토교통부 및 자동차 회사들의 연구자료들을 고찰하였으며, 전기자동차 및 태양광 에너지를 이용한 프로토타입 자동차 사례 또는 근 미래의 기술들의 이론을 바탕으로 연구하였다. 현재 많은 자동차 회사들은 전기 자동차를 대체 에너지로 사용하고 있다. 또한 태양광 에너지로 전기를 보완하는 방식으로 사용하고 있으며, 태양광 에너지를 대체 에너지로 사용하고자 하는 노력을 하고 있다. 연구 결과 태양광 에너지만을 사용하여 자율주행 자동차를 운전이 아닌 운행할 수 있는 실현성이 있다고 보인다. 더 나아가 자동차를 능동적으로 사용하며 태양광 에너지의 사용 및 공급 가능할 것이며 자동차 산업의 미래에 기여할 수 있는 가능성을 제시하고자 한다.

탄소계 경질 박막의 연구 및 산업 적용 동향 (Trend in Research and Application of Hard Carbon-based Thin Films)

  • 이경황;박종원;양지훈;정재인
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 춘계학술대회 논문집
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    • pp.111-112
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    • 2009
  • Diamond-like carbon (DLC) is a convenient term to indicate the compositions of the various forms of amorphous carbon (a-C), tetrahedral amorphous carbon (ta-C), hydrogenated amorphous carbon and tetrahedral amorphous carbon (a-C:H and ta-C:H). The a-C film with disordered graphitic ordering, such as soot, chars, glassy carbon, and evaporated a-C, is shown in the lower left hand corner. If the fraction of sp3 bonding reaches a high degree, such an a-C is denoted as tetrahedral amorphous carbon (ta-C), in order to distinguish it from sp2 a-C [2]. Two hydrocarbon polymers, that is, polyethylene (CH2)n and polyacetylene (CH)n, define the limits of the triangle in the right hand corner beyond which interconnecting C-C networks do not form, and only strait-chain molecules are formed. The DLC films, i.e. a-C, ta-C, a-C:H and ta-C:H, have some extreme properties similar to diamond, such as hardness, elastic modulus and chemical inertness. These films are great advantages for many applications. One of the most important applications of the carbon-based films is the coating for magnetic hard disk recording. The second successful application is wear protective and antireflective films for IR windows. The third application is wear protection of bearings and sliding friction parts. The fourth is precision gages for the automotive industry. Recently, exciting ongoing study [1] tries to deposit a carbon-based protective film on engine parts (e.g. engine cylinders and pistons) taking into account not only low friction and wear, but also self lubricating properties. Reduction of the oil consumption is expected. Currently, for an additional application field, the carbon-based films are extensively studied as excellent candidates for biocompatible films on biomedical implants. The carbon-based films consist of carbon, hydrogen and nitrogen, which are biologically harmless as well as the main elements of human body. Some in vitro and limited in vivo studies on the biological effects of carbon-based films have been studied [$2{\sim}5$].The carbon-based films have great potentials in many fields. However, a few technological issues for carbon-based film are still needed to be studied to improve the applicability. Aisenberg and Chabot [3] firstly prepared an amorphous carbon film on substrates remained at room temperature using a beam of carbon ions produced using argon plasma. Spencer et al. [4] had subsequently developed this field. Many deposition techniques for DLC films have been developed to increase the fraction of sp3 bonding in the films. The a-C films have been prepared by a variety of deposition methods such as ion plating, DC or RF sputtering, RF or DC plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance chemical vapor deposition (ECR-CVD), ion implantation, ablation, pulsed laser deposition and cathodic arc deposition, from a variety of carbon target or gaseous sources materials [5]. Sputtering is the most common deposition method for a-C film. Deposited films by these plasma methods, such as plasma enhanced chemical vapor deposition (PECVD) [6], are ranged into the interior of the triangle. Application fields of DLC films investigated from papers. Many papers purposed to apply for tribology due to the carbon-based films of low friction and wear resistance. Figure 1 shows the percentage of DLC research interest for application field. The biggest portion is tribology field. It is occupied 57%. Second, biomedical field hold 14%. Nowadays, biomedical field is took notice in many countries and significantly increased the research papers. DLC films actually applied to many industries in 2005 as shown figure 2. The most applied fields are mold and machinery industries. It took over 50%. The automobile industry is more and more increase application parts. In the near future, automobile industry is expected a big market for DLC coating. Figure 1 Research interests of carbon-based filmsFigure 2 Demand ratio of DLC coating for industry in 2005. In this presentation, I will introduce a trend of carbon-based coating research and applications.

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일제강점기 '전위미술론'의 전통관 연구 - '문장(文章)' 그룹을 중심으로 (A Study on Avant-Garde Fine Art during the period of Japanese Colonial Rule of Korea, centering on 'Munjang' (a literary magazine))

  • 박계리
    • 미술이론과 현장
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    • 제4호
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    • pp.57-76
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    • 2006
  • From the late 1920s to the 1930s, Korea's fine art community focused on traditional viewpoints as their main topic. The traditional viewpoints were discussed mainly by Korean students studying in Japan, especially oil painters. Such discussions on tradition can be divided into two separate halves, namely the pre- and post-Sino-Japanese War (1937) periods. Before the war, the modernists among Korea's fine art community tried to gain a fuller understanding of contemporary Western modern art, namely, expressionism, futurism, surrealism, and so forth, on the basis of Orientalism, and borrow from these schools' in order to create their own works. Furthermore, proponents of Joseon's avant-garde fine arts and artists of the pro-fine art school triggered debate on the traditional viewpoints. After the Sino-Japanese War, these artists continued to embrace Western modern art on the basis of Orientalism. However, since Western modern fine art was regressing into Oriental fine art during this period, Korean artists did not need to research Western modern fine art, but sought to study Joseon's classics and create Joseon's own avant- garde fine art in a movement led by the Munjang group. This research reviews the traditional view espoused by the Munjang group, which represented the avant-garde fine art movement of the post-war period. Advocating Joseon's own current of avant-garde fine art through the Munjang literary magazine, Gil Jin - seop, Kim Yong-jun and others accepted the Japanese fine art community's methodology for the restoration of classicism, but refused Orientalism as an ideology, and attempted to renew their perception of Joseon tradition. The advocation of the restoration of classicism by Gil Jin-seop and Kim Yong-jun appears to be similar to that of the Yasuda Yojuro-style restoration of classicism. However, Gil Jin-seop and Kim Yong-jun did not seek their sources of classicism from the Three-Kingdoms and Unified Silla periods, which Japan had promoted as a symbol of unity among the Joseon people; instead they sought classicism from the Joseon fine art which the Japanese had criticized as a hotbed of decadence. It was the Joseon period that the Munjang group chose as classicism when Japan was upholding Fascism as a contemporary extremism, and when Hangeul (Korean writing system) was banned from schools. The group highly evaluated literature written in the style of women, especially women's writings on the royal court, as represented by Hanjungnok (A Story of Sorrowful Days). In the area of fine art, the group renewed the evaluation of not only literary paintings, but also of the authentic landscape paintings refused by, and the values of the Chusa school criticized as decadent by, the colonial bureaucratic artists, there by making great progress in promoting the traditional viewpoint. Kim Yong-jun embraced a painting philosophy based on the painting techniques of Sasaeng (sketching), because he paid keen attention to the tradition of literary paintings, authentic landscape paintings and genre paintings. The literary painting theory of the 20th century, which was highly developed, could naturally shed both the colonial historical viewpoint which regarded Joseon fine art as heteronomical, and the traditional viewpoint which regarded Joseon fine art as decadent. As such, the Munjang group was able to embrace the Joseon period as the source of classicism amid the prevalent colonial historical viewpoint, presumably as it had accumulated first-hand experience in appreciating curios of paintings and calligraphic works, instead of taking a logical approach. Kim Yong-jun, in his fine art theory, defined artistic forms as the expression of mind, and noted that such an artistic mind could be attained by the appreciation of nature and life. This is because, for the Munjang group, the experience of appreciating nature and life begins with the appreciation of curios of paintings and calligraphic works. Furthermore, for the members of the Munjang group, who were purists who valued artistic style, the concept of individuality presumably was an engine that protected them from falling into the then totalitarian world view represented by the Nishita philosophy. Such a 20th century literary painting theory espoused by the Munjang group concurred with the contemporary traditional viewpoint spearheaded by Oh Se-chang in the 1910s. This theory had a great influence on South and North Korea's fine art theories and circles through the Fine Art College of Seoul National University and Pyongyang Fine Art School in the wake of Korea's liberation. In this sense, the significance of the theory should be re-evaluated.

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공기조화, 냉동 분야의 최근 연구 동향 -2004년 및 2005년 학회지 논문에 대한 종합적 고찰- (Recent Progress in Air Conditioning and Refrigeration Research - A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2004 and 2005 -)

  • 최영돈;강용태;김내현;김만회;박경근;박병윤;박진철;홍희기
    • 설비공학논문집
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    • 제19권1호
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    • pp.94-131
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    • 2007
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.