Wataru Harano

Combustion Characteristics of Wood Powder and A-heavy Oil

The industrial carbon dioxide discharge is a serious problem of the global environment. The biomass is carbon neutral energy and can be used as an alternative fuel. The object of this paper is to cut down the fossil consumption in a small-scale oil-burning furnace by wood powder and A-heavy oil. The wood powder, which has a size of 150 pm and is made of thinned lumber, is blended into A-heavy oil flame. A wood powder nozzle is used to directly supply the wood powder to the flame in the same axial direction. The combustion characteristics are experimentally investigated. As the wood powder increases, the temperature and the calorific value in furnace is increased, CO concentration is decreased. The particulate matter produced by A-heavy oil is significantly decreased. It is found that the wood powder is available to energy saving and emission control.

Nitrous Oxide Emissions from Marine Diesel Engine Sources

The aim of this paper is to study the effect of ship operation on formation of N2O emissions and the influence of temperature changing in the exhaust pipe diesel engine. The data were taken from training ship Fukae Maru during the voyage project in September 2004 and the diesel engine experiment in the laboratory. Data from the Fukae Maru training ship were carried out at different operating conditions. Two sampling points, in the engine room and funnel were set up in the experiment. The N2O analyzer model 46C was used to measure exhaust emissions. A direct-injection diesel engine with naturally aspirated (model NF-19SK YANMAR) single cylinder was employed to test the emission and engine performance. The experiment data shows that in the 15 degree PPA, the nitrous oxide emissions higher than others condition.

Removal of Particulate Matter (PM) and NO x from marine exhaust gas by combining electrostatic water-spraying scrubber and emulsion oil

In this study, experiments were performed with combination using emulsion oil and an electrostatic water spraying scrubber to evaluate effectiveness for simultaneous removal of NOx and Particulate Matter (PM) emissions in marine exhaust gas. The effects of several parameters, such corona power, gas flow rate, on the contaminant removals have been investigated intensively. Total PM removal efficiency was higher than 99% by electrostatic water spraying scrubber and reduction in NO and NOx emission of up to 28-48% and 18-42%, respectively.

The effects of Electrostatic Precipitator in EGR system on the combustion and exhaust gas of marine diesel engines

Exhaust gas recirculation (EGR) is an effective way of reducing NOx, especially in the exhaust gas from automotive engines that has low particulate concentration, by suppressing the peak combustion temperature. Unlike automotive engines, exhaust gas from marine diesel engines that use low-grade fuel with high concentrations of sulphur and abrasive particles cannot be supplied to engine for EGR, unless the particulate is reduced. The author’s previous research indicates that an electrostatic precipitator (ESP) can successfully reduce marine diesel particulate matter. Hence, in this research, a combined EGR and ESP system capable of simultaneously reducing NOx and particulate matter (PM) was developed. The exhaust gas that was treated by ESP was supplied to the air intake manifold under various conditions, and the results show that a combined EGR/ESP system reduces NO and PM concentrations in exhaust gas. The combination system also improves the rate of heat release.

Characteristics of Combustion and Emission of Marine Four-stroke Medium-speed Diesel Engine with High Sulfur Containing Fuel

The amount of sulfur in fuel directly affects the emission of SOx from diesel engines. It also has an effect on the engine performance and emissions of PM, NOx and others. The object of this study is to investigate the influence of sulfur concentration in a medium-speed engine, which is being used as a main engine or dynamo engine in a lot of ships. The fuel used is of the high sulfur containing substance DBDS (Di-tert-butyl Di-sulfide) at various rates in the same “A” heavy oil. The following results were obtained. As the amount of sulfur concentration increases, the brake fuel consumption ratio increases, causing increase of SO2, decrease of NOx and no change of CO2, O2 and CO. ISF increases almost linearly, and though SOF shows a upward tendency at low load, it does not change at normal 75% load. Therefore PM which is the sum of ISF and SOF increases through 25 to 75% load.

Reduction System of Marine NOx and PM by Seawater Electrolysis Scrubber

Agreement of exhaust air pollution and substances from ships included in MARPOL Treaty (73/78) Annex VI of IMO Air Pollution Control, has been enforced since 19 May 2005. Ships by more than 130 kW class of diesel engine that sail within 200 nautical miles from the coast may cause the serious problems of pollution. It is necessary to develop a new control system for the pollutants emitted from the ships. In this study, a scrubber equipment was developed to reduce the pollutants of NOx and Particulate Matters (PM) in the exhaust tube. The equipment has three stage scrubbers that spray seawater, acid and alkaline water were generated by electrolysis of seawater. NO changes nitrocyl chloride (NOCl) with Cl2 in the acid water. This resulted 73% of reduction rate of NO. However, the reduction rate of NO and PM are 14.3% and 70% respectively at exhaust gas flow of 570 l/min.

The Application and Problem of BDF for Diesel Engine

Energy and air pollution have become important issues in recent years. BDF (Bio Diesel Fuel) such as esterified rapeseed oil or soybean oil, on which a lot of research was accomplished, has attracted attention as one of the new energy sources that replaces fossil fuel. Reported researches approved that in comparison with diesel oil, BDF contributes to reducing of particulate matter emission, which is harmful to the human health. Our research objective is to recycle BDF as marine fuel oil. The test was achieved as an application of BDF-mixed Diesel oil to a ship engine (the continuous rated output: 1000PS/2100rpm×2) and reducing of particulate matter emission.

Marine NOx and COx Emissions under Various Operating Conditions

This paper describes NOx and COx emissions from the diesel engine on mini-vessel such as 500GT class vessel under transient operating condition and entering and departing conditions, because the reduction of the marine exhaust emissions has been important subject. And the International Maritime Organization (IMO) advances the prevention of air pollution from ships in 1989. The regulated level of NOx emissions will be decided by the Bulk Chemicals (BCH), in recent years. So the emissions of carbon monoxide (CO), carbon dioxide (CO2), total hydrocarbons (THC), sulfur dioxide (SO2), and nitrogen oxide (NOx), occupy an important part. The transient operating conditions have been formed by change of engine speed and PPA whose region are within the range of 500-673rpm, and 11-20deg. NOx concentration in summer voyage changes within the limits of 600- 1000ppm, and CO2concentration changes within the limits of 4-7%.

Formative Diagnosis of NO&Soot by LIF&LLS methods of YAG Laser

An experimental study was made of two-dimensional visualization on soot particles and NO in steady and unsteady flames by laser sheet. The soot volume fraction are obtained from the scattered light intensity of the soot by LLS (laser-light scattered) method, since the relation between the light intensity and the soot volume fraction by light attenuation method is determined quantitatively. And NO distribution was measured by planar laser-induced fluorescence (LIF) method. It was found that the soot volume fraction lay within the limits of 10-7 and 10-5 (cm3/cm3), and had maxima at the inside of ribbon flame front. The reaction of soot decomposition became actively with the eddy break down over the downstream. The distribution NO and flame temperature showed a similar tendency. LIF intensity of NO agreed relatively with the NO concentration of the sampling gas measured by chemiluminescence method.

Measurement of Soot Concentration in the Gaseous Diffusion Flame by YAG Laser Sheet Method

The measurements of two-dimensional distribution of soot concentration are necessary for better understanding of the conditions of the soot formation and decomposition during the rapid combuston. The YAG laser sheet (50 mm×0.5 mm) of wavelength 532 nm (22mJ/pulse) was used as the light source for Mies theory. The visualization of soot particles was realized by a ICCD camera via a high-speed gated image intensifier. The scattered light images in the C3H8/Air diffusion flame were measured at various cross sections above the nozzle tip. Spatial distribution (maps) plots for the soot volume fraction were obtained in the flame from the inspectional data by the light attenuation techniques. The soot volume fraction lies within the limits of 10-7 and 10-5 cm3/cm3, and have maxima at the near part of flame front.Larger peak values are found in the vicinity of the burner port. Those experimental results agree approximately with the previous data obtained by the light attenuetion technices.