マリンエンジニアリング
Online ISSN : 1884-3778
Print ISSN : 1346-1427
ISSN-L : 1346-1427
49 巻 , 1 号
選択された号の論文の30件中1~30を表示しています
巻頭言
特集 舶用機関におけるガス焚きエンジン及びその周辺の動向について
随想
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技術資料
  • 宇井 岳夫
    2014 年 49 巻 1 号 p. 31-36
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     LNG is considered to be the most promising marine fuel for the near future for two reasons. One reason is that LNG is more “Eco-friendly” than conventional oil fuel. The other is that there is a high likelihood that the price of LNG will be lower than that of conventional oil fuel brought about by emerging new source of LNG like “shale gas”, and by its wider use.
     In response to this situation, Kawasaki Heavy Industries, or KHI, proceeded with the development of an LNG fueled vessel, which uses LNG as the main propulsion fuel, and an LNG fuel supply vessel, which supplies LNG fuel for ships.
     In this article, the author will introduce both the LNG fueled vessel and the LNG fuel supply vessel, and discuss some technical tasks which the marine transportation industry needs to cope with in the near future.
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特集 減速運航
随想
解説
技術資料
解説
技術資料
  • Paul Harrold
    2014 年 49 巻 1 号 p. 88-95
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     From 2010 reduced load operation has become increasingly common amongst ship owners and operators trying to reduce fuel consumption during a period of depressed freight rates. This practice has become widespread across many industry sectors and steady reductions in load have been seen such that operating on 15-30% load is being regularly seen and continued operating at 40-60% load or lower has become standard practice in some companies. This paper aims to explore the impacts of this reduced load operation on the lubrication of Cross Head engines and explain why changes in lubricants or lubricant feed rate have become necessary in order for vessels to operate at these lower loads without risk of corrosive wear damage to cylinder liners and piston rings.
  • Luc Verbeeke
    2014 年 49 巻 1 号 p. 96-99
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     For many decades, the marine industry has been a conservative environment with few changes in legislations and engine design. By the end of previous century, however, the demand for more engine power, followed by increased environmental awareness, triggered tremendous changes in this industry segment.
     Since the economic recession started several years ago, the marine industry faced an increasing need to reduce operating costs. This resulted in operational changes and triggered the need for new vessel-and engine designs. These changes also had an impact on the lubrication of low-speed marine engines.
     The selection of the correct cylinder oil and oil feed rate to balance these new conditions in the engine is more important than ever. Chevron has therefore developed its DOT.FAST service to accompany a full range of high quality cylinder oil grades available to guide its customers in achieving reliable and safe operation.
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  • 光藤 春樹, 石川 航, 内田 誠
    2014 年 49 巻 1 号 p. 119-125
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     Marine Engineers acquire knowledge empirically from monitoring data and checking the conditions of marine engine plants. They make the best use of their knowledge in order to manage their job safely, efficiently and economically. On the other hand, the development of communication technology now allows shore-side managers to collect monitoring data from several marine engine plants. Using this data, shore-side managers gather information which can be useful for supporting ships. However, these useful methods have not yet been completely developed. In this research, our aim is to construct an artificial intelligence system called “Virtual Ship Engineer” or VSE, that can accumulate knowledge based on its own autonomous learning processes in way similar to how marine engineers do. The authors divided this learning process into three phases namely, “Data Predicting Model”, “Knowledge Evaluating Model” and “Knowledge Updating Model” and constructed VSE’s autonomous learning model. In this paper, the authors explain the details of these three models using fuzzy reasoning and the steepest descent method and two simulations by using monitoring data to verify the validity and possibility of VSE’s autonomous learning model.
  • 大橋 厚人, 徐 芝徳, 佐々木 秀次, 塚本 達郎
    2014 年 49 巻 1 号 p. 126-131
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     In the field of automobiles, the full flow dilution system has been made the de facto standard of PM measurement. Partial flow dilution systems have been compared and improved using full flow dilution systems as benchmarks. In a previous report, it was shown that there were differences in PM measurements between these dilution systems. On the other hand, the full flow dilution system cannot be used for marine diesel engines with large exhaust gas flow rates. Since the de facto standard of PM measurement for marine diesel engines has not yet been established, it is necessary to find a certain method which guarantees reliable PM measurement results.
     For this purpose, the authors proposed a method to compare the PM concentration measured simultaneously by two or more partial flow dilution systems based on ISO 8178-1/ JIS B 8008-1.  In order to implement this method, the authors measured the PM concentration simultaneously by two kinds of partial flow dilution systems using two types of marine diesel engines, and compared the values of PM concentration. The results show that the values of the PM concentration measured by the systems were in agreement to within ±30 percent, thus yielding mutually confirming results.
     Furthermore, the cause of these differences in PM concentration between the systems was discussed.
  • Dhimas Widhi Handani, Makoto Uchida
    2014 年 49 巻 1 号 p. 132-141
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     The cost spent for ship operation must be considered when analyzing reliable support systems for main engines. This paper proposes new models in System Dynamics (SD) simulations for determining the reliability index (RI) degradation of ship machineries which are installed in main engine support systems of ships. The purpose of this study is to minimize the total operation cost (CT) of machinery which is comprised of running cost (Cr), maintenance cost (Cm) and downtime cost (Cd). Reliability analysis is taken into account based on data from maintenance records. In this paper, two kinds of optimization models which utilize SD are compared. Model 1, an optimization model without forecasting, utilizes a value of minimum RI as a decision to obtain the lowest CT. The minimum RI is the level of reliability of machinery where maintenance actions need to be taken. Model 2, an optimization model with forecasting, constructs the maintenance judgment by forecasting the value of RI for avoiding the minimum RI before a ship arrives at the destination port. Sea water and fresh water cooling pumps are analyzed as a case study. Model 1 resulted in minimum CT, while model 2 reached a CT lower than the outcome of model 1.
  • 岡 秀行
    2014 年 49 巻 1 号 p. 142-150
    発行日: 2014/01/01
    公開日: 2015/07/07
    ジャーナル フリー
     This paper describes the evaluation of a diagnostic urban wind model with a future goal of using this method to assess indoor airflow in a cargo space of a pure car carrier (PCC). At present, computational fluid dynamics (CFD) simulation is a popular approach to computing indoor airflow. However, it requires a very long computing time when the simulated flow domain is very large, such as in PCC cargo spaces. In contrast, the diagnostic model is very economical with computer time, so that it can be an appropriate tool for practical use, such as in preliminary design process and ship inspection. Thus, the present study focuses on the application of a Röckle-type diagnostic model to indoor airflow simulation. The Röckle-type approach consists of a mass-consistent flow model and empirical parameterizations for determining initial wind fields disturbed by obstacles. As the first step, the recently modified Röckle model has been applied to the numerical simulation of a flow field over a cube mounted on the lower wall of a plane channel. The results obtained are in reasonably good agreement with experimental and CFD results, except for the vortex size and velocity profile within the recirculation zone formed upstream of the cube. Hence, the empirical parameterizations for the frontal eddy region have been modified to improve the prediction accuracy of mass-consistent final velocity fields. It has been found that for practical simulation the modified Röckle model is a promising approach to quickly compute indoor airflow, though further research is required to confirm its validity and versatility.
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