抄録
Ships have many advantages in loading capacities compared with vehicles. If the amount of NOx can be reduced by some way, ships can be equipped with oxygen permeable membranes as an oxygen generator that has recently shown a remarkable improvement in the performance of producing more oxygen for the purpose of PM (Particulate Matter) reduction.
Therefore, the objective of this study is to examine the effect of oxygen addition on exhaust gas emissions for marine diesel engines.
In the experiment oxygen was added to the air suction pipe of a pre-combustion chamber type diesel engine. Then oxygen was added to the exhaust gas pipe before DPF (Diesel Particulate Filter) .
The results were as follows:
(1) Oxygen addition to the air suction pipe of a pre-combustion chamber type diesel engine decreases both ISF (Insoluble Organic Fraction) and SOF (Soluble Organic Fraction) . Oxygen addition works very well especially at all loads for reduction of ISF with an increase of 2% in oxygen concentration.
(2) Although oxygen addition to the air suction pipe of a pre-combustion chamber type diesel engine increases NOx emission. The NOx emission of a pre-combustion chamber type diesel engine is not so much as that of a direct injection type engine. The increase of NOx emission is saturated with further increasing engine load.
(3) DPF was effective even in an ordinary type engine that has mechanical fuel injection system and no supercharger. The reduction rate was superior in ISF compared to SOF.
(4) Oxygen addition before DPF has almost no effect on PM reduction.
