scholarly journals Comparison of NOx and Smoke Characteristics of Water-in-Oil Emulsion and Marine Diesel Oil in 400-kW Marine Generator Engine

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 228 ◽  
Author(s):  
Jungmo Oh ◽  
Myeonghwan Im ◽  
Seungjin Oh ◽  
Changhee Lee

Currently, the exhaust gas of a ship is regulated for nitrogen oxides and sulphur compounds; however, there is no IMO regulation on smoke under discussion. This study investigated the reduction of exhaust gas through ship emulsion fuel, which can simultaneously reduce nitrogen oxides and smoke in ship engines before smoke regulations are established. The combustion and exhaust characteristics were investigated according to the moisture content of emulsion fuel using a 400-kW generator engine. As the water content of the emulsion and the temperature of the combustion chamber increase, micro explosion increases and the combustion period decreases. The nitrogen oxide and smoke from the emulsion fuel used in this study decreased by 7% and 75%, respectively. The nitrogen oxides and soot reductions obtained by the use of emulsion fuel were boosted by micro-explosion of water contained in the fuel during combustion.

Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola

A comparative series of experimental tests has been performed on a 4-stroke multi cylinder indirect injection diesel engine fueled with diesel oil, pure gas-turbine fuel and gas-turbine fuel with additives. The engine has been equipped aimed at monitoring both the overall performances and the variation with time of the pressure in the pre-combustion chamber. Some key parameters have been investigated at different engine speeds and loads (ignition delay, pressure rise in the pre-combustion chamber, power output, specific fuel consumption, exhaust gas temperature) and discussed results are presented.


2020 ◽  
Vol 8 (5) ◽  
pp. 322
Author(s):  
Jinkyu Park ◽  
Iksoo Choi ◽  
Jungmo Oh ◽  
Changhee Lee

Exhaust gases from ships and automobiles have a significant impact on people and the environment. As a result, diesel engines used in land and marine vehicles are gradually being restricted, and low-carbon engines are under development. This study considers marine diesel oil (MDO) that is used in ships to meet the emission regulations required by the International Maritime Organization. This investigation explores the method and application technology for the reduction of nitrogen oxides (NOx) and particulate matter using emulsified fuel and mass-produced dimethyl ether (DME) fuel, which are analyzed. When comparing emulsified fuel and DME fuel to MDO, which is a ship oil, NOx are reduced by 20–45% and the particulate matter is reduced by 60–97%. When emulsified fuel containing moisture is used, the combustion chamber temperature is lowered due to the optimal expansion by moisture contained in the fuel. The particulate matter is also reduced. When DME fuel is used, it reduces the particulate matter by more than 97% in comparison with the existing MDO fuel and the emulsified fuel. The conditions are believed to be suitable for combustion and they can be satisfied by supplying oxygen during post-combustion.


2011 ◽  
Vol 282-283 ◽  
pp. 47-50
Author(s):  
Xue Dong Feng ◽  
Yan Fei Ma

Volatilization of diesel oil in sand columns was conducted at the ambient temperature of 20 °C by spilling oil on the sand surface. The weight loss of oil was determined by pre and post weight of the sand columns and desiccant was measured on an electronic balance. The aim of this paper was to investigate the effect of moisture content on the volatilization of diesel oil in sand. The results show that the diesel oil and water in sand both volatilize at a linear rate with respect to time. The largest volatilization mass of diesel oil and water reach when the moisture contents are 8% and 20% respectively. Appropriate water content can help to pull the oil contaminants to the surface of the sand.


1995 ◽  
Vol 1995 (1) ◽  
pp. 435-422 ◽  
Author(s):  
Tsutomu Tsukihara

ABSTRACT Crude oil spilled in the sea is mixed with the sea water by the wind and waves resulting in increases in its water content and viscosity as time passes. We have constructed a small, transfer type circulating water channel of an elliptical cuit-track form. Using an attached circulating unit, together with a war tunnel, artificial waves are generated to enable simulation corresponding to the natural circumstances in the sea. The experiment disclosed the following results.Drastic changes in the properties (water content and viscosity) of the oil depend on the power of waves.Contrasting processes are observed between heavy and light crude oils during weathering.Heavy crude oils form a massive water-in-oil emulsion (mousse) with increases in both water content and viscosity.Light crude oils behave differently at summer sea temperatures,


2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Lijiang Wei ◽  
Anmin Wu ◽  
Jie Liu ◽  
Mingliang Zhong ◽  
Xuebai Wang

For the two-stroke marine diesel engine, the action of exhaust valve has a significant impact on scavenging and combustion processes and ultimately affects the engine performances and emissions. In order to reduce nitrogen oxides (NOx) emissions of a two-stroke marine diesel engine, different exhaust valve lifts (EVLs) were achieved by computational fluid dynamics simulation method in this study. The NOx reduction effect and influence mechanism of EVL on a two-stroke marine diesel engine were investigated in detail. The results showed that the in-cylinder residual exhaust gas and the internal exhaust gas recirculation (EGR) rate gradually increased with the decreasing EVL. Although the total mass of charge enclosed in the cylinder did not change much, the composition changed gradually and the maximum internal EGR rate reached 13.17% in this study. The maximum compression pressure and combustion pressure both rose first and then decreased with the decreasing EVL. While the start of combustion and the maximum combustion temperature were basically unaffected by EVL, the indicated power of the engine was also not much impacted when the EVL was changed from increasing 10 mm to decreasing 20 mm. The indicated specific fuel consumption first declined slowly and then rose rapidly as the EVL reduction exceeded 20 mm. NOx emissions decreased monotonously with the decreasing EVL. The reduction of NOx formation rate and the amount of NOx formation mass mainly occurred at the middle and late stages of combustion for the downward moving of residual exhaust gas. NOx emissions were reduced by 12.57% without compromising other engine performances at medium-reduced EVL in this study. However, in order to further reduce NOx emissions at low EVLs, other measures may be needed to make the residual exhaust gas more evenly distributed during the initial stage of combustion.


Author(s):  
Yoshiyuki Aoyagi ◽  
Masahiro Kaneda ◽  
Keisuke Numahata ◽  
Koji Korematsu ◽  
Junya Tanaka

Abstract In this paper effect of on reduction a Cu-ZSM-5 catalyst of nitrogen oxides is investigated in a diesel engine. This research focuses to solve a problem that there is not enough THC to reduce nitrogen oxides in exhaust gas from a diesel engine. When diesel oil is directly supplied into the exhaust gas, the THC concentration sharply rises and the NOx conversion rate increases. The maximum NOx conversion rate reaches to 63% when the flow rate of diesel oil is 30 ml/min at a catalyst temperature 450 °C. The NOx reduction with less sacrifice of the specific fuel consumption is possible when the fuel is supplied into the exhaust pipe.


2012 ◽  
Vol 220-223 ◽  
pp. 1715-1718
Author(s):  
Yan Zhen Zhang ◽  
Yong Hong Liu ◽  
Ren Jie Ji ◽  
Bao Ping Cai

The gas presented in the discharge gap which was generated by the decomposition and vaporization of the dielectric due to the extremely high temperature in the EDM process plays an important role in the aspect of EDM performance. In this paper, the relative gas volume in the discharge gap is investigated when water-in-oil (W/O) emulsion was used as dielectric. Parameters, such as peak current, pulse duration, water content of the W/O emulsion were researched. Experimental results show that the relative gas volume in the discharge gap was significantly affected by discharge energy. Besides the discharge energy, water content of W/O emulsion is another significant factor that affects the gas volume in the discharge gap.


2020 ◽  
Vol 8 (6) ◽  
pp. 452 ◽  
Author(s):  
Kazimierz Witkowski

The article’s applications are very important, as it is only a dozen or so years since the current issues of protection of the atmosphere against emissions of toxic compounds from ships. The issue was discussed against the background of binding legal norms, including rules introduced by the IMO (International Maritime Organization) in the context of the MARPOL Convention (International Convention for the Prevention of Pollution from Ships), Annex VI, with the main goal to significantly strengthen the emission limits in light of technological improvements. Taking these standards into account, effective methods should be implemented to reduce toxic compounds’ emissions to the atmosphere, including nitrogen oxides NOx and carbon dioxide CO2. The purpose of the article was, based on the results of our own research, to indicate the impact of the effectiveness of selected methods on reducing the level of nitrogen oxides and carbon dioxide emitted by the marine engine. The laboratory tests were carried out with the use of the one-cylinder two stroke, crosshead supercharged diesel engine. Methods of reducing their emissions in the study were adopted, including supplying the engine with fuel mixtures of marine diesel oil (MDO) and rapeseed oil ester (RME)-(MDO/RME mixtures) and changing the fuel injection parameters and the advance angles of fuel injection. The supply of the engine during the tests and the mixtures of marine diesel oil (MDO) and rape oil esters (RMEs) caused a clear drop in emissions of nitrogen oxides and carbon dioxide, particularly for a higher engine load, as has been shown. The decrease of the injection advance angle unambiguously makes the NOx content in exhaust gas lower.


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