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The spray characteristics and inside flow of a marine diesel injector were investigated both experimentally and numerically. From the experiments, we observed that the penetration of the sprays in the early injection stage gradually increases. This phenomenon differs significantly from that of the small automobile diesel injector, in which penetration increases linearly with time. Using the momentum method to obtain injection rate measurements, we observed an injection rate spike at each injection event just after the injection began. The observed spray results show that the small portion of fuel remaining inside the nozzle from the previous injection event is ejected first, and then the main volume of fuel is ejected. Both fuels accumulate as spray droplets and gradually accelerate after the early injection stage. Numerical simulations of the injector's inside flow show that the fuel injection rate becomes saturated in needle lifts larger than 0.3 mm.

Methanol steam reforming, which is an endothermic reaction, needs some heating. Both methanol conversion ratio and carbon monoxide (CO) concentration increase when temperature is elevated. As CO poisons a typical polymer electrolyte of a fuel cell, the relationship between methanol conversion ratio and CO concentration is a trade-off one. It was found from preliminary researches that the reforming reaction speed is controlled by heat transfer rate at large methanol flow rate, where methanol conversion ratio becomes lower and CO concentration becomes higher. Therefore it is necessary to develop a new methanol reforming concept that provides stable combustion for heating and enhanced heat transfer for improving the trade-off relationship and making a compact reformer. Reforming catalyst using metal honeycomb support and a new catalytic combustion were applied to a new concept plate type methanol steam reformer, which is used in a fuel cell of 3 kW-class electric generation.

This paper presents the numerical simulation method to predict the deactivation process of three-way catalytic converters. Three-way catalytic converter's deactivation typically results from thermal and chemical mechanisms. The major factor of thermal deactivation is the sintering of noble metal particles, which is known to depend on the ageing temperature and the oxygen concentration in the exhaust gas. The chemical deactivation is mainly caused by the poisoning, which has two effects on the catalyst deactivation. One effect is the loss of the catalyst activity, which is expressed by reduced frequency factors of reaction rates. Another effect is the suppression of the noble metal sintering. Poison deposits prevent the noble metal particles from moving in the washcoat, assisted by the reduced thermal loading of reaction heats, which is caused by the loss of the catalyst activity. Modeling these deactivation factors, we propose the rate expression of noble metal sintering.