レイアウト線図上の大型2サイクル機関のNOx排出特性 [in Japanese] NOx Emission Characteristics of Large Bore 2 Stroke Diesel Engines in Area of Layout Diagram [in Japanese]
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The marine large bore 2 stroke diesel engines have their own layout diagram defined by the certain range of mean effective pressure p<SUB>me</SUB> and also of the engine speed n. The customers can select voluntarily any combination of power and speed in this layout diagram as the MCR point of his engine. In relation to the exhaust emission regulation by IMO, it is very important and urgent subject to clarify the NOx emission characteristics of the engines in the layout diagram.<BR>In this paper, the behavior of the maximum gas temperature in cylinder T<SUB>max</SUB> in the layout diagram was analyzed and also the many NOx emission data on the shop trials were investigated. Consequently, the following facts have been clarified.<BR>The NOx emission values on the E3 mode in the IMO Technical Code coincide relatively well with those on 100% load. Therefore the evaluation and analysis of the NOx emission characteristics can be executed by means of the NOx emission values on 100% load.<BR>The value of the degree of explosion p<SUB>max</SUB>/pc correlates closely with T<SUB>max</SUB>, and also T<SUB>max</SUB> correlates closely with the NOx emission values. One of the cause of the relatively large dispersion of the NOx emission values is the scattering of the p<SUB>max</SUB>/pc on the shop trials.<BR>In case of the p<SUB>me</SUB> derating in the layout diagram, if the slope of p<SUB>s</SUB>/p<SUB>me</SUB> to p<SUB>me</SUB>/p<SUB>me0</SUB> is set to be approx. -0.11, then the value of ps/pme is made to increase along with the decrease of p<SUB>me</SUB>/p<SUB>me0</SUB> by the matching and the value of T<SUB>max</SUB> is kept to be almost same, subsequently the value of NOx is kept also almost same.
- Marine Engineering
Marine Engineering 34(4), 243-252, 1999-04-01
The Japan Institute of Marine Engineering