Emission control systems with chemical and physical sensors

1. In order to meet the more and more stringent emission regulations gasoline as well as diesel engines will need continuously improved exhaust after treatment systems. The options for the various applications are highlighted in the following. Today exhaust gas of gasoline engines is typically treated with “Three Way Catalysts” (TWC). The catalyst converts the pollutants CO, NO_X and Hydrocarbons into harmless compounds like CO₂, H₂O and N₂ by chemical reactions. Lambda-Sensors control the air fuel ratio of the engine and catalyst performance in order to get the best possible conversion of the pollutants.

2. Modern lean burn engines have other options. Here the pollutants in the exhaust gases are only partially converted by a TWC function i.e. CO and Hydrocarbons. For the remaining NOX a so called NOX Storage Catalyst (NSC) is employed, which chemically stores NO and NO₂ during lean burn phase. For the conversion of stored NOX the engine is periodically shifted to fuel rich operation. This more complex system is controlled with the help of mathematical catalyst models and by Lambda-, Temperature- and optionally NOX-Sensors as well.

3. Diesel engine exhaust of heavy duty vehicles will be treated with ammonia by Selective Catalytic Reduction (SCR) to reduce NOX additionally to the catalytic oxidation of CO and Hydrocarbons. The ammonia is generated on board of the vehicle using harmless precursors like for example urea. For the control of this system Lambda-, Temperature- NOX- and optionally NH₃-Sensors are employed.

4. In addition to gaseous pollutants the particulate emissions from diesel engines will be removed by Diesel Particulate Filters (DPF). The system of oxidation catalyst and DPF is controlled by Temperature-, Pressure- and Particulate-Sensors. The mentioned highlights show that all three goals safe, clean and efficient can be met in the future by both gasoline and diesel engines combined with modern exhaust after treatment systems.

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Unit 2

New Words

Nouns

1	Cam	Кулачок
2	Torque	Крутящий момент
3	Bulkhead	Перегородка
4	connecting rod	Шатун
5	Throttle	Дроссельная заслонка
6	bore and stroke	диаметр цилиндра и длина хода
7	knock	детонационный стук в двигателе
8	crankshaft	коленчатый вал
9	capacity	емкость
10	reliability	надежность

Verbs

1	evolve	развивать
2	explore	исследовать
3	mate with	соединять с чем-л.
4	be biased toward	быть рассчитанным на что-л.
5	feature	иметь особенность
6	employ	использовать
7	Pressurize	повышать давление
8	incorporate	включить

Adjectives

1	Direct	Прямой
2	Variable	изменяемый
3	homogenous	Однородный
4	smooth	гладкий/плавный
5	forged	Кованый
6	Liquefied	cжиженный /жидкий
7	conventional	Обычный
8	secure	Безопасный
9	unique to	присущийтолько

Adverbs

1	approximately	приблизительно
2	Internally	между собой
3	Infinitely	непрерывно
4	Steadily	постоянно
5	continuously	непрерывно
6	Initially	первоначально