The rest of 3 ships are equipped with the steam turbine, with the total output of 59,100 kW (80,376 PS).
2.3 Studies at Ship Research
Institute
Emission control from ships will be scheduled to come into force on and after January 1,2000 because the Protocol to add the Annex specifying the air pollution prevention to the International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978 relating thereto (MARPOL 73/ 78) was adopted by IMO (the International Maritime Organization). In addition, the engines for transport are regarded recently to be a problem as major source of generation of CO2 N 20, etc., which are the substances to cause the global warming effect, the Ship Research Institute has been challenging the researches concerning reduction of harmful exhaust gas to be emitted from marine engines in order to control the air pollution by ships.
Studies in 1997：
(1) A study on the effect of the fuel composition on the harmful exhaust gas
The effect of the difference in the conditions of operating the engines and fuel properties on the composition of the harmful exhaust gas was studied by changing the kind of fuel oil to be used in the medium-speed 4-cycle diesel engine for experimental use. As a result, the increase in N2O was more remarkable as the residual fuel contains more sulfur. The emission characteristics of N20 by the fuel are indicated in Fig. 2.3-1.
Fig. 2.3-1 N20 Emission Characteristics by Fuel
(2) A study on water emulsion fuel operation
In order to understand the problems in the fuel injection system to be suitable for the water-emulsion fuel operation, the capacity of the fuel pump and the kind of the fuel valve were changed in the test engine, and the effect of the fuel injection characteristics on the combustion by the water emulsion fuel and the NOx reduction effect were studied. As a result, promotion of atomization of the fuel by using the fuel valve of small nozzle hole diameter was effective to improve the combustion, but the NOx reduction ratio at the same water addition ratio (the ratio of water to be mixed in fuel) was reduced. Fig. 2.3-2 shows the emission characteristics of NOx by the difference in the nozzle hole diameter of the fuel valve and the water emulsion fuel.
(3) A study on deNOx equipment for marine use
The selective catalytic reduction system was installed, and the reduction effect of NOx to various operational conditions was analyzed using the test engine, and the effectiveness to marine diesel engines was examined.
(4) A study on evaluation of harmful exhaust gas from ships and examination on the trend
Pursuant to the study in the previous year, the effect of the operational condition of the ships and the secular changes on the emission of the harmful exhaust gas was examined through the measurement of exhaust gas on actual ships based on the joint research with the Maritime Safety Agency and the Institute for Sea Training.
