• 제목/요약/키워드: Delivery feed rate

검색결과 22건 처리시간 0.032초

대형 2행정 디젤기관의 모터구동 주유기 유량 및 송출 특성에 미치는 실린더 배압의 영향에 관한 연구 (A Study on Effect of Cylinder Back Pressure on Feed Rate and Delivery Characteristics of Motor-driven Lubricator in a Large Two-stroke Diesel Engine)

  • 배명환;정화;옥현진
    • 한국자동차공학회논문집
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    • 제13권5호
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    • pp.19-28
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    • 2005
  • It is of great economic importance to minimize the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine. The motor-driven cylinder lubricator was first developed fur a large two-stroke marine diesel engine made in $W{\ddot{a}}rtsil{\ddot{a}}a$ Switzerland Ltd. by the joint research of industry-university. In this study, the effects of revolution speed, plunger stroke and cylinder back pressure on maximum discharge and delivery pressures, delivery delay duration, and oil feed rate are experimentally investigated by the home-manufactured cylinder lubricator. The maximum discharge pressure with a spot of 0.03 m and the maximum loss pressure at spots of 5, 6.78 and i 0 m away from the end of lubricator slot are increased as plunger stroke, revolution speed and back pressure are elevated, and the delivery delay duration is shortened as plunger stroke, revolution speed and oil pipe length are increased. Also, oil feed rate is increased as plunger stroke and revolution speed are raised, but lowered as the back pressure is increased.

대형 2행정 디젤기관에 있어서 전자제어 퀼 부착 모터구동 실린더 주유기의 송출유량 특성에 관한 연구 (A Study on Feed Rate Characteristics of Motor-driven Cylinder Lubricator with Electronic Control Quill in a Large Two-stroke Diesel Engine)

  • 배명환;정화;정연학;김인덕;강창호
    • 한국자동차공학회논문집
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    • 제15권6호
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    • pp.1-8
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    • 2007
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, authors first developed a motor-driven cylinder lubricator for a Wartsila Switzerland large two-stroke diesel engine. The characteristic of the developed product is that can control automatically the oil feed rate with a load fluctuation by the motor drive and the offset cam. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and to improve performances as a cylinder lubricator. In this study, the effects of pump motor speed, plunger stroke and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the electronically controlled quill injection system and distributer in the developed cylinder lubricator. It is found that the oil feed rates of electronic control and mechanical type quills with the in-cylinder back pressure are differently characterized by the role of accumulator, the viscous resistance of contact area, etc. It can be also shown that the maximum discharge pressure of the electronic control quill is lower than the mechanical type one but the maximum discharge pressure difference of two types decreased as plunger stroke is small, and the maximum delivery pressures of two types increased as plunger stroke, motor speed and back pressure are elevated but the maximum delivery pressure of mechanical type is higher than the one of electronic control type.

대형 2행정 디젤기관용 모터구동 실린더 주유기의 성능에 미치는 퀼 어큐뮬레이터의 영향에 관한 연구 (A Study on Effect of Quill Accumulator upon Performance of Motor-driven Cylinder Lubricator in a Large Two-stroke Diesel Engine)

  • 배명환;옥현진;정화
    • 한국자동차공학회논문집
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    • 제15권2호
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    • pp.115-125
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    • 2007
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, a motor-driven cylinder lubricator for a large two-stroke marine diesel engine manufactured by $W{\ddot{a}}rtsil{\ddot{a}}$ Switzerland Co., Ltd. was first developed by authors through the joint research of industry-university in 2002. The characteristic of the developed product is that can control automatically the oil feed rate to a load fluctuation by the motor drive and the offset cam. The performance of the product is not also inferior to the conventional one. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and improve the performance of a cylinder lubricator. In this study, the effect of quill with and without accumulator on maximum discharge pressure, delivery delay duration and oil feed rate relative to motor revolution speed using plunger stroke as a parameter is experimentally investigated by using the developed cylinder lubricator. It is found that the maximum discharge pressure with accumulator is higher than that of no accumulator as plunger stroke and motor revolution speed are elevated, and the delivery delay duration with accumulator is shorter than that of no accumulator as plunger stroke and motor revolution speed are increased. Also, oil feed rate with accumulator is less than that of no accumulator except for a plunger stroke of 2 mm as plunger stroke and motor revolution speed are raised.

대형 2행정 디젤기관에 있어서 축압분배기 부착 전자제어식 퀼 시스템 모터구동 실린더 주유기의 송출유량 특성에 관한 연구 (A Study on Feed Rate Characteristics of Motor-driven Cylinder Lubricator by the Electronically Controlled Quill System Equipped with an Accumulating Distributor in a Large Two-stroke Diesel Engine)

  • 배명환;정화;배창환
    • 한국자동차공학회논문집
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    • 제19권4호
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    • pp.91-98
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    • 2011
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of mounting a quill system to lubricate cylinder parts for smoother operation. In order to apply the common-rail lubricating system to the developed cylinder lubricator as the second research stage, the quill system with a progressively quantitative distributor is improved in the electronically controlled quill system with an accumulating distributor. In this study, the effects of lubricator motor speed, plunger stroke and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the electronically controlled quill system with an accumulating distributor in the developed cylinder lubricator. It is found that the oil feed rate of the electronically controlled quill system with an accumulating distributor is larger than that of the quill system with a progressively quantitative distributor because of the increase of delivery speed and volume by changing the location of accumulator in the same experimental condition.

대형 2행정 디젤기관에 있어서 일체형 전자제어 축압분배 실린더 주유기 시스템의 송출유량 특성에 관한 연구 (A Study on Feed Rate Characteristics of Integrated Cylinder Lubricator System with an Accumulated Distribution by the Electronic Control in a Large Two-stroke Diesel Engine)

  • 배명환;정화;배창환
    • 한국자동차공학회논문집
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    • 제20권6호
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    • pp.52-60
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    • 2012
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of modifying the lubricating system to lubricate cylinder parts optimally by an electronically controlled quill device according to changes of engine load and revolution speed. In order to apply the developed accumulating distributor to an integrated cylinder lubricator by the electronically controlled system as the third research stage, the lubricating system is improved in the electronically controlled quill device with a solenoid valve. In this study, the effects of lubricator revolution speed, driving pressure and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the integrated cylinder lubricator system with an accumulated distribution by the electronic control. It is found that the oil feed rate of the developed integral cylinder lubricator system is less than that of the motor-driven cylinder lubricator by the electronically controlled quill system equipped with an accumulating distributor because of the decrease of delivery speed by increasing the maximum delivery pressure in the same experimental condition.

대형 2행정 디젤기관에 있어서 일체형 전자제어 축압분배 실린더 주유기 시스템의 주유 불균일률에 관한 연구 (A Study on Inequality Rate of Integrated Cylinder Lubricator System with an Accumulated Distribution by the Electronic Control in a Large Two-stroke Diesel Engine)

  • 배명환;정화;김수민;배창환
    • 한국자동차공학회논문집
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    • 제22권2호
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    • pp.123-133
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    • 2014
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of improving the lubricating system to lubricate cylinder parts optimally by an electronically controlled quill device according to changes of engine load and revolution speed. In order to apply the developed accumulating distributor to an integrated cylinder lubricator by the electronically controlled system as the third research stage, the lubricating system is improved in the electronically controlled quill device with a solenoid valve. In this study, the effects of lubricator revolution speed, driving pressure(or plunger stroke) and cylinder back pressure on oil feed rate and lubrication inequality rate are investigated by using the integrated cylinder lubricator system with an accumulated distribution by the electronic control(I.C.S.), and the oil feed rate and lubrication inequality rate of I.C.S. are compared with those of the motor-driven cylinder lubricator by the electronically controlled quill system equipped with an accumulating distributor(E.D.S.). It is found that the oil feed rate of I.C.S. is smaller than that of E.D.S. due to the reduction of delivery velocity by the higher delivery pressure, and the variances of lubrication inequality rate for I.C.S. have become smaller than those of E.D.S. as the driving pressure in all experimental conditions increases, except for the driving pressure of 26 bar(plunger stroke 2 mm) at the cylinder lubricator speed of 120 rpm.

단기통 4행정 농용 디젤기관의 개발 연료펌프 성능특성에 관한 연구 (A Study on Performance Characteristics of the Developed Fuel Pump for a Single-cylinder Four-stroke Agricultural Diesel Engine)

  • 배명환;이상해;정화
    • Journal of Advanced Marine Engineering and Technology
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    • 제40권9호
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    • pp.756-761
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    • 2016
  • 본 연구에서는 소형 단기통 4행정 농용 디젤엔진에 장착될 수 있는 플런저 직경 4 mm, 행정 7 mm의 연료펌프를 설계 및 제작하여 성능특성을 조사하는 것이 목적이다. 실린더 내 연소압력은 자체 제작한 모형 실린더 내에 질소가스를 사용하여 1, 6, 11, 16 및 21 bar의 배압을 형성시켜 모사했다. 실험에 있어서는 연료펌프 회전속도를 600, 800, 1000, 1200 및 1400 rpm로 변화시키면서 개발된 연료펌프의 토출구에서 1 cm 떨어진 지점의 토출압력, 30 cm 떨어진 지점의 송출압력과 송출유량을 배압에 대해 측정하였고, 펌프효율을 계산하였다. 그 결과, 연료펌프 회전속도가 증가하면 펌프의 송출유량은 증가하였고, 실린더 내의 압축압력인 배압이 증가하면 송출유량은 감소하였다. 또한, 연료펌프의 회전속도가 증가할수록 펌프효율이 감소되었고, 실린더 내의 배압이 증가함에 따라 펌프효율은 감소되었다.

대형 2행정 디젤기관용 축압분배기 부착 전자제어식 퀼 시스템 모터구동 실린더 주유기의 주유 불균일률에 관한 연구 (A Study on Inequality Rate of Lubrication for Motor-driven Cylinder Lubricator by the Electronically Controlled Quill System Equipped with an Accumulating Distributor in a Large Two-stroke Diesel Engine)

  • 배명환;정화;배창환
    • 한국자동차공학회논문집
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    • 제20권3호
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    • pp.26-36
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    • 2012
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of mounting a quill system to lubricate cylinder parts for a smooth operation. In order to apply the common-rail lubricating system to the developed cylinder lubricator as the second research stage, the mechanical quill system with a progressively quantitative distributor (M.D.S.) is improved in the electronically controlled quill system with an accumulating distributor (E.D.S.). In this study, the effects of lubricator motor speed, plunger stroke and cylinder back pressure on oil feed rate and inequality rate are experimentally investigated by applying E.D.S. to the developed cylinder lubricator. It is found that the oil feed rate of E.D.S. is higher than that of M.D.S. because of the increase of delivery speed and volume by changing the role of accumulator in the same experimental condition. It can be also shown that, in E.D.S., the inequality rate is decreased a little or hardly unchanged as the cylinder back pressure and plunger stroke is elevated, while the inequality rate increased in M.D.S.. The inequality rates of E.D.S. and M.D.S. are lowered as the lubricator motor speed is increased.

모유수유 실천과 관련 요인 (A Study on Factors Related to the Practice of Breast-feeding)

  • 박천만
    • 보건교육건강증진학회지
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    • 제19권2호
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    • pp.23-43
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    • 2002
  • Purpose: The purpose of this study is to examine and analyse factors related to the actual status and practice of breast-feeding during an infant period to grasp elements detrimental to breast-feeding and, therefore, provide basic information useful for its effective practice and encouragement. Method: From April 1 to June 30, 2001, this study was carried out with the mothers of 337 who were 6 months old, as of the surveyed date, of infants born in 2002 and registered in Seongju-gun Public Health Center, Gyeongsangbug-do Province. The method for its survey included both of the visiting and telephone interviews, and questions were mainly about the mothers' general characteristics(3 questions), infants' general characteristics(3 questions), environmental characteristics of infant delivery( 4 questions), support to breast-feeding(4 questions), understanding of breast-feeding(5 questions), and feeding type during the 1 to 6-month period after birth. Result: 1. The feeding type during the I-month period after birth showed that the breast-feeding accounted for 42.4%, which was higher than dry milk-feeding(30%) or mixed milk-feeding(26.8%). However, it began to be lower than the dry milk-feeding from the 2-month period after birth. During the 6-month period, the breast-feeding accounted for 28.6% which was lower than 56.5% of the dry milk-feeding. 2. The mothers who were encouraged by their delivery clinic to and were educated to breast-feed infants accounted for 55.4% and 41.4%, respectively, which were relatively low. The understanding of breast-feeding indicated that the responses were positive from the view point of mother & infant health, but negative from mother's physical form. 3. It was shown that the lower the educational background of mother(p〈0.05) and the higher the unemployment of mother(p〈0.001), the higher the positive understanding of breast-feeding, and that the higher the entire support to breast-feeding, the more positive their understanding. 4. It was also shown that the lower the educational background of mother(p〈0.05), the higher the unemployment of mother(p〈0.001), the more the experience in breast-feeding at a delivery clinic(p〈0.01) and the faster the initial feeding(p〈0.001), the higher the rate of breast-feeding. 5. The factor having an effect on breast-feeding included a delivery clinic's encouragement to breast-feed(p〈0.001), understanding of breast-feeding(p〈0.01), father's comment on feeding method(p〈0.05) and mother's employment(p〈0.05). Discussion: In order to encourage the breast-feeding, as shown above, it is required, fist of all, to offer pregnant women an education about importance and excellence of breast-feeding and its appropriate method before delivery in advance to result in a positive comprehension of the breast-feeding. To do that, both the publicity activities and program development designed to encourage the breast-feeding must be performed in advance at the government level. In addition to that, the mother-infant space as ‘rooming-in’ available for breast-feeding immediately after delivery must be prepared on the basis of legal and administrative support. Finally, female employees' leave after childbirth must be performed for the purpose of productive welfare and circumstances also be prepared for breast-feeding, such as a children's home at work.

Rumen Microbes, Enzymes and Feed Digestion-A Review

  • Wang, Y.;McAllister, T.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권11호
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    • pp.1659-1676
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    • 2002
  • Ruminant animals develop a diverse and sophisticated microbial ecosystem for digesting fibrous feedstuffs. Plant cell walls are complex and their structures are not fully understood, but it is generally believed that the chemical properties of some plant cell wall compounds and the cross-linked three-dimensional matrix of polysaccharides, lignin and phenolic compounds limit digestion of cell wall polysaccharides by ruminal microbes. Three adaptive strategies have been identified in the ruminal ecosystem for degrading plant cell walls: production of the full slate of enzymes required to cleave the numerous bonds within cell walls; attachment and colonization of feed particles; and synergetic interactions among ruminal species. Nonetheless, digestion of fibrous feeds remains incomplete, and numerous research attempts have been made to increase this extent of digestion. Exogenous fibrolytic enzymes (EFE) have been used successfully in monogastric animal production for some time. The possibility of adapting EFE as feed additives for ruminants is under intensive study. To date, animal responses to EFE supplements have varied greatly due to differences in enzyme source, application method, and types of diets and livestock. Currently available information suggests delivery of EFE by applying them to feed offers the best chance to increase ruminal digestion. The general tendency of EFE to increase rate, but not extent, of fibre digestion indicates that the products currently on the market for ruminants may not be introducing novel enzyme activities into the rumen. Recent research suggests that cleavage of esterified linkages (e.g., acetylesterase, ferulic acid esterase) within the plant cell wall matrix may be the key to increasing the extent of cell wall digestion in the rumen. Thus, a crucial ingredient in an effective enzyme additive for ruminants may be an as yet undetermined esterase that may not be included, quantified or listed in the majority of available enzyme preparations. Identifying these pivotal enzyme(s) and using biotechnology to enhance their production is necessary for long term improvements in feed digestion using EFE. Pretreating fibrous feeds with alkali in addition to EFE also shows promise for improving the efficacy of enzyme supplements.