マリンエンジニアリング
Online ISSN : 1884-3778
Print ISSN : 1346-1427
ISSN-L : 1346-1427
44 巻 , 2 号
選択された号の論文の29件中1~29を表示しています
随想
報告
解説
技術資料
  • 三浦 信之
    2009 年 44 巻 2 号 p. 193-198
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    In order to predict the vibration and noise level in a ship by simulation, and achieve optimum design, it is therefore required to evaluate accurately engine the exciting forces running through the engine installation base. However, generally it is difficult to calculate engine exciting forces, such as combustion pressure, unbalanced inertia force by piston and connecting rod, and unbalanced rotating inertia force by the crankshaft. So, the measurements of exciting forces of actual engine were tried by use of two methods. The results are described as follows.
  • 椎原 裕美, 岡本 和之, 黒澤 忠彦
    2009 年 44 巻 2 号 p. 199-207
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    Machinery in ships is normally checked by inspection, under open conditions, periodically. Recently however, the intention to operate by condition monitoring, but without open-up inspection, is being considered. Under a circumstance of the ISO standards for condition monitoring procedures. ISO have issued the certification procedure for technicians, concerning the vibration monitoring started in some countries, in accordance with ISO18436. Nippon Kaiji Kyokai has investigated optimum condition monitoring methods for the diesel engine, especially for the main bearings. Some successful evidence is showing the effectiveness of high frequency vibration monitoring, and lubricating oil monitoring. This is a result of field testing: using large main diesel engines, and with the cooperation of engine manufacturers, shipyards and ship-owners. Some effective monitoring methods for plane bearing will be explained with the results of the authors' investigation.
解説
随想
技術資料
  • Matthias Amoser, Konrad Räss
    2009 年 44 巻 2 号 p. 226-231
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    Piston-running behaviour remains one of the key determining factors in the reliability and time between overhauls for the diesel engine. This paper reports on some of development work with Wärtsilä large-bore, low-speed marine diesel engines. This has resulted in much improvement. The work led to better specifications for the cylinder liner surface morphology, standardisation on the chrome-ceramic coating for all piston rings, and improved distribution of cylinder lubricating oil on the surface of the cylinder liner. Shipboard testing dismissed the hypothesis that water droplets were reaching the cylinder liner surface. The overall results were confirmed by long-term trials on a fleet of ships.
  • Henrik Rolsted, Jesper Weis Fogh
    2009 年 44 巻 2 号 p. 232-238
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    The present design of piston ring packs and cylinder liners represents a development driven by environmental regulations, reliability and operating costs of two-stroke engines.The use of low-sulphur fuels, now a reality in several SECA (Sulphur Emission Control Area), an increasing demand from shipowners to be able to operate the engines without major overhauls between dockings and the cost of lube oil are some of the elements which have led to the present design for cylinder condition.This development started in the mid-1990s, resulting in the introduction of a new design in year 2000. Development in the area of lubrication has led to a new lubricator, the Alpha Lubricator. As a result of research, it has been possible to lower the feed rate significantly over the past 5 years.
  • 若月 祐之, 山本 智勝
    2009 年 44 巻 2 号 p. 239-246
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    The present design of piston ring packs and cylinder liners represents a development driven by environmental regulations, reliability and operating costs of two-stroke engines.The use of low-sulphur fuels, now a reality in several SECA (Sulphur Emission Control Area), an increasing demand from shipowners to be able to operate the engines without major overhauls between dockings and the cost of lube oil are some of the elements which have led to the present design for cylinder condition.This development started in the mid-1990s, resulting in the introduction of a new design in year 2000. Development in the area of lubrication has led to a new lubricator, the Alpha Lubricator. As a result of research, it has been possible to lower the feed rate significantly over the past 5 years.
解説
技術資料
  • 竹島 茂樹, 有本 直純
    2009 年 44 巻 2 号 p. 266-272
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    From the end of the 1990s to the beginning of the 2000s, engine manufacturers have developed high-output, high-efficiency engines. At the same time engine manufacturers have improved cylinder lubrication. However, emission regulation requires a low base number cylinder oil for low sulfur fuel. Oil suppliers have been developing products corresponding to these demands. In order to understand recent technology trends in lubricants (system oil and cylinder oil) for two-stroke crosshead diesel engines, the performance of formulations a decade ago and the latest ones are compared. The deposit formation control performance of system oils differ, depending on brand. High temperature extreme pressure properties and high temperature detergency, of high base number cylinder oils, was improved about 20 degree C over the past ten years. Moreover, low base number cylinder oils and universal cylinder oils developed after 2000 have a higher temperature extreme pressure property, and a higher temperature detergency and oxidation stability equivalent when compared with the latest high base number cylinder oils.
  • 羽根田 誠, 永井 義和, 森脇 利統, 矢田部 孝, 菅原 広
    2009 年 44 巻 2 号 p. 273-278
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    As marine diesel engine output increases, the combustion chamber will be put under ever much strain. Recently, the contamination of Bunker Fuel Oil by FCC has seriously damaged moving parts and wear and tear of them have reportedly affected the safe navigation of ships. In order to know the wear and tear of moving parts within the combustion chamber, inspection and maintenance are carried out at anchor; if wear and tear could be studied on board at sea, such data could improve engine operation and help to prevent engine troubles. Let us introduce the skill of continuous monitoring and analysis of cylinder oil drain from large-output marine diesel engines. Consequently, a reduction in the amount of cylinder oil used will contribute to cutting costs.
解説
報告
連載
技術資料
  • 宮田 修, 菅澤 忍, 小島 隆志, 柴田 俊明, 千田 哲也, 柴田 清, 渡邉 兼人
    2009 年 44 巻 2 号 p. 292-297
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    In order to measure the release rate of anti-foulant from a ship's hull paint, paint specimens were mounted on a ship and their loss of thickness after sailing was measured. Specimens were prepared by coating conventional paints onto steel plates. The major anti-foulants were cuprous oxide and copper pyrithione. They were mounted on bilge keel of a training ship. After sailing, the specimens were collected periodically and the coating thickness measured. The average release rate, estimated from the thickness differences, varied from 11 to 40 μg/cm2/day. The release rate increased throughout the voyage when both average sailing speed and water temperature remained high. Observations of the cross section of a coating revealed formation of a skeleton layer near the surface where anti-fouling substances had leached out. Obtained release rates and the observed coating structures, are similar to those in laboratory tests which used rotating cylinders.
論文
  • 脇坂 知行, 藤本 英史, 伊藤 和真, 高田 洋吾
    2009 年 44 巻 2 号 p. 298-303
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    Gasoline homogeneous charge compression ignition (HCCI) engines, in which a very lean homogeneous mixture is burned at a high compression ratio, can operate with a high thermal efficiency, and can reduce NOx emission. Therefore, the HCCI engine is a possible candidate as a next-generation engine. In this study, the authors newly proposed a reduced elementary reaction scheme for gasoline PRF, and simulated the ignition and combustion process and the combustion products in a gasoline HCCI engine by three-dimensional numerical analysis using the authors' GTT code, which was linked to the CHEMKIN subroutines with the proposed elementary reaction scheme. As a result, the ignition timing, the cylinder gas pressure, the rate of heat release, and the emissions of NO and CO2 at various air-fuel ratios and engine speeds were accurately predicted.
  • 徐 芝徳, 古堅 宗勝, 牧野 義, 塚本 達郎
    2009 年 44 巻 2 号 p. 304-309
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    In this research an Electrostatic-cyclone DPF (Diesel Particulate Filter) was developed to reduce the PM (Particulate Matter) emission from a marine diesel engine. Experiments were executed to investigate and estimate the feasibility and collection efficiency of the DPF. The effects of three factors on the PM collection efficiency was investigated; exhaust gas temperature in the DPF inlet, exhaust gas flow rate through the DPF and the length of the discharge electrode. Results show that the Electrostatic-cyclone DPF is suitable for the marine diesel engine. The collection efficiency of PM reached 65% by dilution method and 80% by the opacity smoke-meter method. The exhaust gas temperature had little effect on the collection efficiency.
  • 横田 源弘, 望月 敬美, 平 雄一郎, 島崎 渉
    2009 年 44 巻 2 号 p. 310-315
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    To clarify the effects of cathodic protection on cavitation erosion in seawater experiments were conducted. Four metallic materials were used in conjunction with using a cavitating jet erosion apparatus. They were pure copper C1100BD-H, stainless steel SUS316; second type titanium TB340C and the third, titanium alloy Ti-6Al-4V. The results were as follows: (1) The mass loss of each metallic material decreases remarkably with the increase of the cathodic current. The current density of the effective protection is approximately 0.07 [A/cm2] under test conditions. (2) Under cathodic protection the cushioning effect of the protective film of the adhesion product decreases with the mass loss, as do the hydrogen gas effect and anticorrosive effect, etc. (3) Cavitation erosion resistance in seawater, and under cathodic protection, can be evaluated in terms of macro hardness (HV). These are improved when the average hardness or the cathodic current increases.
  • 張 雲志, 清水 悦郎, 伊藤 雅則
    2009 年 44 巻 2 号 p. 316-321
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    This paper introduces a new type of parallel mechanism, i.e. a 6-STRT, and its application to shipping. This mechanism consists of 6-sliders of horizontal motion and 6-links, of which the lower ends are connected to the sliders and the upper ends to the end plate; this via universal joints. The mechanism can move the end plate to 6 degrees of freedom. The authors succeeded to make the end plate perfectly stable, and regardless of all kinds of hull motions. In this paper, the authors are going to refer to motion and performance analysis of this mechanism by the matrix-vector method. The motion control of this mechanism will be shown in the next paper.
  • 段 智久, 橋本 正孝, 浅野 一郎, 奥村 哲平, 鈴木 直樹
    2009 年 44 巻 2 号 p. 322-327
    発行日: 2009年
    公開日: 2012/04/20
    ジャーナル フリー
    DME is the simplest ether and consists of oxygen and methyl. Because of its chemical and physical properties it is thought that DME could be one of the candidates as an alternative fuel in the internal combustion engine. The authors have been investigating the combustion characteristics of the mixed fuel comprising of Dimethyl ether and Marine Diesel Oil (JIS A-heavy oil). In the experiments, DME is mixed at the liquefied state with MDO inside a high pressure fuel tank pressured with nitrogen gas. Fuel supply lines are replaced with pressure resistant tubes, and the mixed fuel is supplied to the small direct injection diesel engine. We obtained the effect on the fuel injection characteristics to the mixed fuel combustion, in the diesel engine. The two different fuel injection rates are obtained by changing the injection nozzle opening pressure, that for the relatively lower case (9.0MPa) and higher (24.0MPa). The fuel injection pressure histories and the combustion characteristics, such as the combustion pressure and the exhaust emission, are examined for both the injection conditions. The average injection pressure increased with increased engine load in the lower nozzle opening pressure case. Whilst it is almost constant with the higher nozzle opening pressure case. It was concluded that ignition delay could be shortened by DME mixing. And NOx emissions were reduced in the higher engine load case, and with mixing DME for both nozzle opening pressure cases.
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