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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.

Three-dimensional numerical analysis of fuel liquid and mixture behavior in a port-injection gasoline engine is assessed by comparing calculations with measurements. The fuel mass distributed in the intake port and cylinder is measured using an engine with hydraulic valve and gas sampling system. The experimental results show that about half of the fuel mass per injection enters the cylinder, and the rest stays in the port. The difference of the mass fraction of injected fuel directly entering the cylinder is small between the cases of single pulse injection and serial injection. Therefore, three-dimensional calculation presupposing single pulse injection has difficulty in predicting the in-cylinder mixture formation process, although it can analyze the amount of fuel wetting the port wall. The calculations are performed for a port-injection engine, and the differences of fuel behavior with respect to swirl control valve opening and wall temperature are discussed.

A new heating strategy for electrically heated catalysts has been developed which reduces power consumption while achieving the desired hydrocarbon conversion. The relationship between catalyst volume and power consumption is presented. Observations of catalytic reactions by a thermoviewer camera and mathematical simulations are used to optimize the heating pattern. Significant reductions in power consumption, while maintaining conversion efficiency, are reported by heating only the front face of the catalyst. However, prior to mass production additional work is required to improve durability, and reliability and to resolve manufacturing issues.