Revision of MARPOL 73/78 Annex VI was adopted (resolution MEPC.176(58)) at the IMO MEPC 58 (October 2008), and the framework for the regulation of future sulphur reduction was decided. By 2025 at the latest, the global maximum sulphur content in marine fuel oil will be reduced to less than or equal to 0.5 %m/m. Aside from the phased reduction of sulphur, IMO is considering whether other fuel properties need to be controlled. The effects of the reduction of sulphur in fuel oil have already been felt, and with future step-by-step sulphur reduction, there is concern that these effects will aggravate. Therefore, it is necessary to pay due attention to the changing circumstances regarding marine fuel oil with a wider perspective.This report mainly describes the situation to date of fuel oil standards and marine fuel oil properties.

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Current and foreseen marine fuel legislation is targeted towards prescribing the maximum sulfur content of fuel oil or to reduce the sulfur in exhaust gases with alternative methods equivalently.The availability of fuels with various sulfur levels is not yet fully clear. However, with the demand to reduce the sulfur content in the fuel to below 0.5%, the possibility of an operator receiving distillate fuel increases. Hence, operators need to be prepared to use distillate fuel correctly.

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This paper introduces the latest development and technical explanation of ME-GI dual fuel two-stroke engines and gas fuel supply system for gas application on LNG/LPG carriers and marine vessels in general.In cooperation with well-known and experienced gas handling partners, MAN Diesel offers safe and reliable high-efficient prime movers for LNG carriers.By optimising the engine and gas supply systems using state-of-the-art technology, in cooperation with our gas system partners, we have actively lowered investment and operational costs, and generally improved system efficiency. Thereby, a positive effect has been achieved on the total fuel consumption as well as the overall environmental impact on the surroundings.

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Due to the existing and coming environmental legislation on fuel sulphur contents MAN B&W two-stroke engines will increasingly operate on distillate fuels, marine gas oil (MGO) and marine diesel oil (MDO), in such areas where demanded.MAN B&W two-stroke engines are optimised to operate on heavy fuel. The MGO / MDO fuels can be used, however, some individual considerations on the Engine and fuel system have to be done to ensure safe and reliable performance.Traditionally, the lowest viscosity suitable for large marine diesels has been set at 2 cSt at engine inlet, however experience has shown us that the most reliable performance is achieved with viscosities above 3 cSt at engine inlet.Fuels with a specified viscosity of minimum 2 cSt at 40 deg C can be used, however as many factors influence the performance operating on fuels in the low viscosity range, MAN Diesel believes that fuels with a viscosity of 3 cSt at 40 deg C hold the sufficient margin for safe and reliable engine performance

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DME is widely gaining acceptance as an alternative fuel for diesel engines. DME is a clean fuel that does not emit soot, PM, and SOx. It has a high cetane number, and is suitable for diesel engines. According to its exhaust characteristics, NOx reduction is easily attained by engine tuning and by applying a large amount of EGR. Focusing on these advantages, JFE Engineering and Daihatsu Diesel have jointly developed a DME diesel power generation system and constructed a 1250kW DME demonstration plant. Technical tests for various elements and continuous endurance tests were completed, and its potential for practical use was confirmed. This paper describes the outline of the world's first large-scale power generation DME plant, presents distinctive test results, and also describes the future of DME fuel.

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In LNG carriers, a part of the cargo is converted to boil-off gas due to heat from the open air and ship motions. Steam turbines have been predominantly used for current propulsion systems of LNG carriers, because this boil-off gas can be used as fuel for boilers. However, in recent years the number of electric propulsion systems using dual-fuel diesel generator engines has increased as an alternative to steam turbine systems. Last November, NIPPON KAIJI KYOKAI (ClassNK) issued the "Guidelines for Dual-Fuel Diesel Engines". These guidelines describe the construction and applicable rules for dual-fuel diesel engines. The IGC Code and Chapter 16, Part N of the Society's Rules prescribe the requirements that apply to dual-fuel diesel engines on the "Use of cargo as fuel". Furthermore, "Annex 3" and "Annex 4", Part N of the Guidance to the Society's Rules describe the requirements in detail for dual-fuel diesel engines. This paper gives an overview of the Guidelines mentioned above.

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This paper gives an insight into the present status in the world with regarding the use of natural gas as a fuel in ships, based on DNV's extensive experience and knowledge. In Norway, the number of LNG-fuelled ships in operation has grown from 0 to 14 ships in the last 9 years, and the basics of some of these ships will be presented. The gas engine fundamentals will be outlined, as well as the basic framework for safe installations and the status of international rules. The future potential of a fuel cell driven ship will also be included, with main emphasis on the research project FellowSHIP.

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Bio gas fueled engines have proved effective in helping the environment; such as reducing methane gas which has a large greenhouse effect, alongside an ozone layer destructing effect, because the main composition of bio gas is methane, and it is not emitted into the atmosphere, but burned up within the engine. In this study, by combining the GRI-Kojima reduced elementary reaction scheme and the DME reduced elementary reaction scheme, which had been constructed by the authors' group, the authors constructed a reduced elementary reaction scheme originally for the mixture of bio gas, city gas, DME and air for investigating the combustion characteristics of a bio gas and city gas mixture fueled engine which was ignited with DME (dimethyl ether) spray. On the basis of chemical kinetics with the proposed elementary reaction scheme, the authors conducted three-dimensional numerical analysis of the combustion process within a practical computation time in a bio gas and city gas mixture fueled engine which was ignited with a small amount of DME spray, using different mixture ratios of bio gas and city gas.

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Dimethyl ether (DME) is one of the most promising alternative fuels for the near future. For rapid spread, it is desirable to use the mixture of DME with LPG (mainly propane), because a mature supply infrastructure already in existence can be employed. However, using the mixture of LPG and DME as a fuel for a spark ignition engine causes a problem, knocking during combustion. In a previous study, the authors analyzed this knocking phenomenon in a small gas engine for co-generation system by means of a three-dimensional combustion simulation based on a chemical kinetic model, and investigated the effect of combustion chamber shape on the knocking phenomenon. However, due to long computational time, it was difficult to evaluate various piston cavity shapes under the wide range of operating conditions. Therefore, in this study, the authors have investigated the effects of those piston cavity shapes on engine performance, especially on knocking limits by experiments under the wide range of operating conditions in the same engine, and have explored a suitable piston cavity shape for LPG-DME mixture fuel with high ratio of DME.

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This paper reports on numerical analysis, by use of discrete phase model (DPM). This is helpful to specify the cause of wear occurring with a ship's piping system. It has occurred, during trials, that the flow in the pipe has eroded the coated inside wall of pipe bends. These damage occurred over a short time. The cause was thought to be slurry erosion, and not corrosion. The seawater often contains sand particles. Therefore, the DPM simulations and experiments were conducted on a mixed flow with sand particles, past the constrictions created by bends in the pipe. Comparing the experiments with the DPM simulations, the actual damage by the sand particles was found to be on the same area predicted by the DPM simulations. We consider the DPM simulation is able to clarify that the damage is caused by slurry erosion.

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When difficulties are encountered during the hybridization of ships through solar battery systems, the hybridization method of collecting heat from the engine exhaust gas during the ship's voyage through some thermoelectric element should be considered. In this paper, the authors propose that the ship's intermittent loads be driven by a battery power supply, while the other constant electric loads are supplied by a diesel generator prime mover unit with an efficient and stable output.

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A series of experiments was performed on a circulating fluidized bed (CFB) in order to investigate effects of the rolling motion on gas-solid heat transfer in the riser. Superficial velocity was changed in the experiments, while amplitude of the rolling motion and rolling period were fixed at 15deg. and 6s, respectively. The following results were obtained: (1)Heat transfer at the riser walls was dominated by collision between particles and the wall. Therefore, it depends on change of the gas-solid flow near to the wall region. Namely, heat transfer is augmented by the downflow of particles in the upper/mid part of the riser, and is promoted by the particles drifting on the distributor, in the lower part. (2)When the CFB stands upright, heat transfer rate in the upper/mid part grows gradually with the increase of the superficial velocity through activation of the downflow. On the other hand, the heat transfer rate in the lower part of the riser decreases rapidly with the superficial velocity increase, which reduces the suspension density through the flow regime change. (3)When the CFB undergoes the rolling motion, the downflow along the riser walls periodically changes, and the contact between particles and the walls is promoted. As a result, the heat transfer rate in the rolling motion is larger than that at upright attitude in the upper/mid part of the riser. In the lower part of the riser, the heat transfer rate also increases notably by the rolling motion, which increases suspension density there.

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In the experimental evaluation in transparent materials, generally optical techniques are often used. However, marine engine components are consist of metals, which are opaque materials. Therefore, visualization of stresses in metallic materials was almost impossible.In this paper, the intelligent hybrid method made it possible to visualize highly accurate stress and strain components in metallic materials.

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In the experimental evaluation in transparent materials, generally optical techniques are often used. However, marine engine components are consist of metals, which are opaque materials. Therefore, visualization of stresses in metallic materials was almost impossible.In this paper, the intelligent hybrid method made it possible to visualize highly accurate stress and strain components in metallic materials.

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