Particulate in exhaust gas of diesel engine includes soots as aromatic compound and unburned carbon which constituents of fuel oil are changed. The major reason for the existence of particulate is due to incomplete burning of fuel oil. A method of combustion matching with properties of fuel oil can control the existence of particulate. To do so, it is necessary to clarify how constituents of fuel oil are aromatized and carbonized. This paper presents the results of investigation into distribution of aromatized hydrocarbon compound in accordance with the number of benzene rings after introducing all of cracked gases produced by heated samples into gaschromatograph. The samples were Sa, Ar, and Re fractions that were separated from fuel oil C by column chromatograph. These fractions were pyrolyzed by an electric oven under desired temperature 400-800°C in an atomosphere of nitrogen. From the results of measurements mutual relationship of these fractions was sufficiently estimated as follows: When fuel oil C heated at 800°C, aromatic compounds in cracked gases were more in number than other kinds of hydorocarbons; and Re content in the fuel oil influenced amount of unburned carbon.
This paper describes the fruit of the project by The Technological Research Association of Highly Reliable Marine Propulsion Plant. A future marine diesel engine will be required with superior performance, output, efficiency and reliability using degraded fuel. It has attendant requirements of wear characteristics and strength of cylinder components far exceeding those of conventional engines. Ceramic base composite material was developed and coated on pistonrings and cylinderliners by using a low pressure plasma splay process. They were tested by full scale test engines in the objective “future” conditions. As a result, the wear of plasma coated pistonrings and cylinderliners were small enough to prolong overhauling interval to 4 years. Plasma spraying coating process also makes possible to apply strong materials for cylinerliner.
The last investigation about actual circumstances of wear of low speed, long stroke 2 stroke marine diesel engines, clarified their abnormal wear conditions. Since then makers have taken various countermeasures against them, and in order to confirm their actual effects, Japan Ship Owners Association has been collecting wear data. This report describes the analysis results of wear conditions as to the types discussed at the last investigation, based on the data of two years (April 1987 - March 1989) . 1. Statistics of Oil Feed Rate of each type There are no differences between the actual feed rates converted in catalogue MCO of A type and C type. 2. Analysis of Wear Rate of Liner and Piston Ring Liner wear characteristics of A type is getting stable comparing with the last investigation. But on the contrary, excessive wear of ring takes place similarly on A type, C type and D type. 3. Analysis of Oil Feed Rate-Wear Rate It has been clarified that wear rate differs with each diesel maker. 4. Analysis Derating Rate-Wear Rate-Oil Feed Rate The higher wear rate is found out in the higher derating engine, and it is clarified that the oil feed rate on high derating engine is too small.
The experienced crew can diagnose the fuel oil line by the touch on the fuel injection pipe. The aim of this research is to develop a new diagnostic system for the fuel oil line of marine diesel engine by the sense of touch in order to substitute for the crew's diagnosis. This paper discusses the experiment of diagnosing the fuel oil leakage from the fuel injection pump by the accelerometer fixed on the fuel injection pipe. The original vibration is analysed through (1) power spectrum analysis, (2) filtering analysis, and (3) absolute value analysis. The distinctive signal is found at the time of the combustion. The attenuation time of the signal at the normal condition becomes shorter than that at the abnormal.
Diesel engines have now become almost the only means of ship propulsion and severe competition has developed among engine makers. The improvements which have been made to diesel engines are analyzed in this paper with particular emphasis on specific output and thermal efficiency. The Mitsubishi UE engine is used as an example. Also the struggle among engine makers is reviewed. Finally, the reasons for the continued survival of the Mitsubishi UE engine are touched upon.
This paper indicates the whole contents of 8 chapters in the electric technical history of the Japanese Warships and Merchant vessels, which is written by the above sub-commitec regarding to all the electrical equipment progression in the Japanese War-ships and Merchants Vessels before 1945. The above history has been published already on the journal of “Fune no Kagaku” between 1984 and 1990. As these works have been completed mostly by the relief of The Japan Ship-building Industly Foundation, our members express gratitude to the favour. The history containts as follows. 1) electrical installation 2) electrical apparatus 3) electrical navigation instruments 4) radio and electromic apparatus 5) degaussing equipments of ships 6) electrical propulsion