디젤 주기관의 DERATING에 관한 연구
|dc.description.abstract||As a movement of cargo and passenger is increasing in currently, the transportation of the vessel occupies much of them. To the vessel, the source power has been very important to propel the vessel as well as the space of the cargo. Therefore, it was interested to owner and manufacturer to take the cheaper and more efficient engine which is suitable for the vessel. Ship's main power source is called 'Main Engine', and that must be selected properly because it is the one of the most important equipments. In the matter of the designing of the ship or saving the expense, the efficiency of the main engine is very important. So there are some requirements should be satisfied as the main engine, which are the low SFOC(specific fuel oil consumption), low malfunction and high reliability, convenient maintenance and low maintaining expense, easy operating, low efficiency reduction despite long-term use, a few number of crew in the engine room, light weight and small volume, low vibration and noise, cheap price, and so on. But there is nothing to be satisfy all these requirements. The main engine will be developed and taken in the vessel, which has a output from a few horsepowers to more than 130,000 BHP (MAN B&W 14K 108MC & ME ENGINE). The oil crises in 1973 and 1979 caused considerable effort to decrease the fuel consumption. As a result, the main engine is being changed through the shape(from loop scavenging air system to uniflow scavenging air system), higher compression ratio, low speed and long stroke. The operation system also being changed cam shaft controlled engine into electronically controlled engine. The changes of this sort contribute to not only a improvement of the SFOC as a final object, but also a decrease of air-pollution for healthy life as a common object. If the main engine is producted and supplied in need of various condition, it's the best ideal. It is difficult to make a various engine satisfied with all factors, various cargo, adaptability in various weather condition, change of navigation condition, a various request of owner, expended cargo area according to owner's request, change of oil price, etc. The engine manufacturers have tried to get a solution to satisfy consumer's request. So they could find a way that can change the rating through large range from the engine already manufactured. The ways changing the rating are modifying scavenging air pressure, adjusting the compression ratio through changing compression shim, adjusting the timing of exhaust valve and modifying a diameter of nozzle of fuel injection valve etc. These ways are tried through large range to change rpm to 72% and engine's output to 48% of MCR with keeping the normal engine's shape almost. The important elements considered in the process of derated output of the main engine are not only about safety and extension of machine's length of life, but also about how can you recover the beginning overcapitalization as soon as possible through low SFOC. And then these act also have to fit the profit among owner, manufacturer, and operator. At the study, try to compare and consider between rating and derating through this research with several data about modifying rating which have been done by engine manufacture so far. So this study shows, - definition of the rating - producing basis and analysis of each of the graph which constitute load diagram which is used for setting the limitation of a load for the successive operating of the main engine - the relationship between engine output and rpm -the relationship between engine torque and mean effective pressure - engine derating that should be done and consideration of the method - a strong point and a weak point when engine derating - the interrelation in the matter of expense in long-time operation - the propeller efficiency when engine derating -the item that should be consider when engine derating and it had been chosen the various comparative standards and make several ships(used for derating) which had been made by differing manufacturer an object of scientific study, and then it had been compared and examined difference with regular engine.||-|
|dc.description.tableofcontents||Abstract ⅳ 제 1 장 서 론 1 제 2 장 엔진 출력의 정의 4 2.1 출력의 각종 정의 4 2.1.1 연속최대출력(MCR)과 상용출력(NCR)의 관계 7 2.2 동력의 전달 과정과 정의 8 2.2.1 도시마력(IHP-indicated horse power) 8 2.2.2 마찰손실마력(FHP-frictional horse power) 9 2.2.3 제동마력(BHP-brake horse power) 9 2.2.4 축마력(SHP-shaft horse power) 9 2.2.5 전달마력(DHP-delivery horse power) 10 2.2.6 추진마력(THP-thrust horse power) 10 2.2.7 유효마력(EHP-effective horse power) 11 2.3 선박의 소요 마력 산정 11 2.4 지시마력과 제동마력의 관계 13 2.5 평균유효압력(Mean Effective Pressure -MEP) 14 2.6 엔진 정격을 제한하는 주변 요소들 15 제 3 장 부하선도에 대한 해석 17 3.1 동력과 회전수의 관계 17 3.2 추진기 법칙 18 3.3 부하 선도의 구성 요소 20 3.4 부하 선도 내에서 기관의 운전 점 설정 23 3.4.1 기준점 23 3.4.2 회전수 상한선 23 3.4.3 출력 상한선 23 3.4.4 평균유효압력 상한선 24 3.4.5 회전력(평균유효압력) 제한선 24 3.4.6 과부하 운전 한계선 25 3.4.7 운항선에서 출력 예측을 통한 엔진 부하 계산법 25 3.5 토크 리치 현상과 프로펠러 마진 27 3.5.1 토크 리치 현상 27 3.5.2 프로펠러 회전수 마진 28 3.6 시마진(sea margin) 31 3.7 프로펠러 법칙에 의한 부하와 회전속도와 관계 33 제 4 장 엔진 derating에 대한 정의 및 실적선 비교 36 4.1 Derating의 정의 36 4.2 Derating의 목적 및 효과 38 4.3 Derating을 적용한 선박의 실례 42 4.4 동일 엔진의 공칭정격과 derating 비교 검토 46 4.5 다른 선체에 동일 엔진을 탑재 후 derating을 실시한 선박들의 주변기기들의 특성 비교 48 제 5 장 Derating의 범위 설정 53 5.1 엔진의 선택 53 5.2 각 제작사별 타입별 분류 67 제 6 장 Derating의 방법과 최적화(optimizing) 84 6.1 Derating의 방법에 대한 예 84 6.2 각 Derating 점에서의 기관조정 87 6.2.1 소기압력 87 6.2.2 간극용적 [압축 심(shim) 두께] 87 6.2.3 배기 타이밍(timing) 87 6.2.4 연료밸브 노즐경 88 6.3 Derating시의 장점 및 단점 88 6.3.1 장점 88 6.3.2 단점 89 6.4 Derating과 엔진 최적화(optimizing) 관계 89 제 7 장 결론 92 참고문헌 94||-|
|dc.title||디젤 주기관의 DERATING에 관한 연구||-|
|dc.title.alternative||A Study on Derating of Diesel Main Engine||-|
|dc.contributor.alternativeName||Go - Ryong||-|
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