An experimental study was made to investigate in-cylinder combustion in a spark-ignited natural gas engine and its dependence on engine running conditions. Flame propagation in a single-cylinder visualization engine was measured from the cylinder axis direction by the high speed schlieren method, over the wide range of spark timing and excess air ratio. The results showed that flame did not propagate concentrically around spark plug electrode, but was shifted by swirl flow. The gravity center of flame area moves corresponding to flow field in the combustion chamber. In the case of partial-burning, flame left from the spark plug electrode, resulting in no more propagation. Cylinder pressure increase is delayed compared to flame propagation. Heat release is detected when flame area occupies around 4% of the combustion chamber area. Heat release shows its maximum when flame area occupies around 70% of the combustion chamber area. Flame area varies cycle-to-cycle within ±10% to its average, which is smaller than cycle variation of swirl velocity. Spark timing had little effect on flame propagation and its speed. Larger excess air ratio resulted in more slender flame, slower and more shifted flame propagation. Flame propagation speed, which is negatively proportional to excess air ratio, gets half from about 10m/s to about 5m/s as excess air ratio changes from 1.3 to 1.6.
In our previous papers, some experiments by the use of an actual boiler have been carried out in order to investigate the effects of sea water mixing on boiler water qualities, especially on pH, concentrations of PO43- and of Cl-, and Electric Conductivity EC. Experimental study by the use of an autoclav was also carried out in order to investigate the behavior of Mg hardness when OH- and/or PO43- coexisted, and when silica was mixed. The study mentioned above revealed that there was a limitation of the applicability of the conventional chemical reaction model developed so far. This paper considers, therefore, a new model regarding the chemical reaction system of scale components and water treatment chemicals of phosphate/alkali type. The validity of a new proposed model is proved by the comparison of the estimation according to the new model with the experimental result in the case when sea water mixed into boiler water.
Authors have carried out experiments for deNOx performance of small size deNOx plant with platinum-zeolite catalyst and propylene reduction agent, for development of deNOx system with hydrocarbon reduction agent. As result of experiments, following have been found. (1) . The deNOx equipment with hydrocarbon reduction agent is higher reduction efficiency by control of exhaust gas temperature at catalyst. (2) . Supply method of reduction agent influences reduction performance of deNOx equipment, so that divide supply of reduction agent is higher reduction efficiency. (3) . NOx reduction effect of this system with other deNOx method, as fuel injection retard and water emulsified fuel, is comparable without other deNOx method. (4) . After driving this system at about 200 hr, NOx reduction efficiency is not drop.
In accordance with advanced refinery facilities, marine fuel quality tend to heavier and some engine troubles arising from inferior quality of fuel have been reported continuously. Therefore, estimation for the Ignition quality or combustibility of marine fuel in the labolatory is important factor in view of safety operation of vessels or protection of environment. However, the ignition quality regarding with combustibility of fuel oil on low speed marine diesel engines have not been made clear yet in spite of investigation by the thermogravimetry-differential thermal analysis (TG-DTA), the fuel droplet combustion method, the fourier transform Infrared spectrometry (FT-IR) and others. Under such situation, cooperated with Nippon Mitsubishi Oil Corporation and Mitsui O.S.K Lines Investigated the Ignition quality of marine fuel based on Fuel Ignition Analyser (FIA-100), and we herewith report the investigated results.
This paper reports the study on monitoring the cylinder lubricating condition of two stroke marine diesel engine by ferrograph analysis. When the number of large/severe or cutting ferrous wear particles is under 300 per 1 ml cylinder drain oil sample, the cylinder lubricating condition might be very good and be satisfied.
The effect of the amount of asphaltene and carbon residue on the combustion performance, of marine fuel oil, particularly, the exhaust gas temperature and smoke emissions, was analyzed using a 4-stroke diesel engine. When the amount of asphaltene contained in the fuel was increased, the exhaust gas temperature rose and the amount of smoke increased.
This paper presents the useful experimental results of the self-ignition temperature on no existence of the ignition source with regard to heavy fuel oil used mainly for the marine diesel engine. We compare these results with ones of gas oil and marine diesel oil. The ignition temperature of inflammable material is not a constant value. It depends on the characteristics of inflammable material, the mixing ratio with air, the surrounding air pressure, the shape and dimension of a heating body, a measuring apparatus and the method. The purpose of this study is to confirm the self ignition temperature of heavy fuel oil at the atmospheric pressure, dropping oil on the surface of the heat insulator. As a result, it became clear that the boundary temperatures of self-ignite region and not self-ignite region for heavy fuel oils was higher than gas oil and marine diesel oil.