A tendency towards lower quality of marine residual fuel oil (MFO) has been observed due to the steep rise in crude oil costs, increased upgrading of petroleum refining technology and so on. A particular problem involving diesel engines is the deterioration of the combustion quality of MFO. However, there is no international standard regarding ignitability and/or combustibility of MFO at the current moment. Therefore, fuel oil suppliers do not need to pay attention about ignitability and combustibility in the refinement process of crude oil with which MFO is made.Energy Institute (EI) had standardized the method of testing ignition and combustion characteristics of MFO by using constant volume combustion chamber such as Fuel Combustion Analyzer (FCA) in 2006. However, a technical evaluation method concerning the ignition and combustion quality of MFO has not been established yet. And, it is not made clear when such an evaluation method is reflected in the actual international standard.Consequently, the paper presents an investigation result of recent trend of the ignitability and combustibility and general properties of 524 cases of actual MFO samples measured by the international standard test method using FCA. And further describes the relationships among combustion quality, general properties and engine problems.
Although containerization of marine transportation has been bringing globalization to our daily life, it also triggered a dazzling development of technology on marine transportation side as well. Our daily life has become healthy via the development of transportation technology for such as fresh foods, and by use of the marine reefer container. Marine transportation technologies for fresh foods have been tackled with various techniques. We hereinafter introduce the transition technology for transportation by marine reefer container from the beginning of the container age until the present.
In order to handle the increasingly strict environmental standards we looked at the electronic management of the engine, as used for marine applications. This holds one of the most effective solutions to reduce antinomy NOx and CO2 emissions, and at the same time. Electronic-managed two-stroke engines have been with us for some time, though not yet for the four stroke engine, this is because of the high cost. The development of this project is aimed at improving combustion efficiency, NOx reduction, and minimizing the cylinder lubricant dosage rate. This in the operating area, not only of the rated power zone, but also the partial load zone. By managing electronically, the performance excels in a wide operating range. The characteristics of fuel injection, intake and exhaust valve operating time, and the cylinder lubricator, utilize the inherent advantages of the four stroke engine.
For safe engine operation and the most suitable combustion for environment, monitoring of combustion in a cylinder and combustion control technology are important while an electronic control of a marine diesel engine advances. Measurement of Indicated Mean Effective Pressure (IMEP) is needed to monitor combustion conditions. It is thought that the numbers for sampling data can be reduced, and the calculation can be performed faster for real-time combustion monitoring by IMEP. In this paper, the influence of the data sampling interval upon the calculation error of IMEP, and reasons, are analyzed. Concerning the IMEP calculation for the marine diesel engine, the authors use a new calculation method of IMEP, using the low frequency component of cylinder pressure. A conventional calculation method of IMEP uses cylinder pressure and volume change. When data sampling interval was long, the new calculation method which was recommended by the authors was found better than the conventional calculation method of the IMEP.
The stratified air-fuel mixture formation for stratified SI (spark ignition) combustion, and the homogeneous air-fuel mixture formation for both homogeneous SI combustion and HCCI (homogeneous charge compression ignition) combustion, in a direct-injection gasoline engine, have been three-dimensionally analyzed by means of the authors' GTT code with a fan spray model which was validated by the authors' group. The effects of various in-cylinder gas flows on mixture formation, by means of a fan spray, have been investigated by using intake valves with shrouds in various layouts. Furthermore, the effects of the fuel injection direction and the injection timing on mixture formation, have also been investigated. As a result, it has been found that both stratified mixture and homogeneous mixture can be formed stably at a wide range of engine speeds by only changing the fuel injection timing, with the fuel injection direction in accordance with the in-cylinder gas flow direction.
The initial effects of immersion on the release rate of antifouling agents from ships' hull paints were investigated. Rotating cylinder tests were conducted similar to the ASTM/ISO method. Cylinders coated with sample paints were placed and rotated in containers for up to 24 hours. Concentration of leached antifouling agent was measured at specified intervals. Measurement was carried out under various conditions: pH of the solution, composition of the solution (de-ionized water, phosphate buffer solution and substituted ocean water) and the rotating speed of the cylinders. The dissolved chemical species and pH of aqueous solution significantly affected to the release rate of antifouling agent, where the degree of the effect was dependent on the composition of the antifouling paints. The release rates under rotating conditions were higher than that under static conditions, although rotating speed did not much affect the release rate under those of greater than 60 rpm.