Search Results

Reducing the oxides of nitrogen (NOx) and particulate matter (PM) from Diesel engine exhaust gas has become very important problem in view of the protection of environment and the saying energy. But it is difficult to reduce both emissions significantly at the same time by engine modifications and operating condition control. Because, their characteristics have a trade off relation. Therefore many investigators are studying the aftertreatment technique of Diesel engine emissions such as a PM trap filter, EGR, etc. The aftertreatment technique is expected that engine operating condition limits will be loose and engine efficiency will be improved. A few years ago, Iwamoto showed that Zeolite catalyst could reduce the NOx with hydrocarbon reducing agents under oxygen rich condition[1]*. After that, many researchers have been investigating Zeolite catalysts[2]-[4].

In the fields of the internal combustion engines for automobile and marine use, higher output power, higher efficiency and lower fuel consumption are strongly expected. The problems of environment such as a global greenhouse effect or an acid rain is getting worse. Therefore the exhaust gas regulations had been introduced and being strengthen in the USA, Europe and Japan. These regulations demand the reduction of NOx and particulate matter(PM) from diesel exhaust gas at the same time. The turbocharging has been more important technique for these regulations. For automobile engines, it is common to use the pulse turbocharging system for compactness and advantage of response. The characteristics of compressor and turbine are different from under steady state condition by pulsating flow. Especially, it is difficult to estimate the performance of turbine mounted on engine by using the map measured under steady state flow.