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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
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Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология Образование Политология Производство Психология Стандартизация Технологии |
Exercise 6. Say which engine is considered to be more competitive and give reasons
Use the following:
1. its higher compression ratios and lean burn combustion provide high efficiency. 2.its average thermodynamic efficiency is 15 percent better. 3. its pricey after-treatment system crimps (снижает) efficiency. 4. its ethanol-boosted concept makes it possible to achieve thermal efficiency. 5. we see incremental improvements in hardware such as independent cylinder combustion control. 6. its fuel energy density is lower. 7.it still needs regular maintenance to keep it running. 8. its small ignition retard ( запаздывание) makes them more speedy. It is more easily turbo-charged. Exercise 7. Render the following text in English. Engineering firm Ricardo—the company responsible for the seven-speed dual-clutch automated manual in the 1001-hp Bugatti Veyron—has somewhat loftier goals for ethanol. It’s working on a 3.2-liter V-6 engine that could replace a large turbo-diesel V-8 in a heavy-duty truck application. But it’s not as simple as adding boost. The engine internals have to be nearly as strong as those in a modern diesel and just about every piece in Ricardo’s running prototype has been swapped out for a heftier replacement. The twin-turbo EBDI engine has a 10.5: 1 compression ratio and uses two air-to-gas EGR coolers to chill the high-pressure charge, improve thermal efficiency, and to ensure there’s no overfueling of the engine under high boost. Moreover, there are other factors in play. As GM's Grebe points out, diesel fuel contains about 14 percent more energy by volume than gasoline. This gives compression-ignition engines a significant edge in fuel economy, as opposed to thermal efficiency. Of course, everything will change if and when spark-ignited engines switch to more energy-dense fuels. This race is far from over. (1120 characters) Exercise8. Express your opinion about probability /improbability of different types of engine in the future.
The following items will help you: a. better fuel economy. b. they are non -toxic, non-explosive and practically noiseless. c. they are much noisier and tend to vibrate. d. improved after-treatment systems. e. they are environmentally unfriendly. f. they are more economical and environmentally friendly. g. longer engine life. h. their efficiency is much higher. i. they can run on an alternative fuel (biodiesel or vegetable oil).. j. the improvements in electronics and materials. k. they are more powerful and reliable. l. they are heavy and occupy much space. m. long failure-free operation. n. limited charging extra weight and high maintenance cost. o. they are easier to maintain Exercise 9. Topics for reports: 1. The engine of the future. 2. A great future is in store for electrical cars. 3. Transport and the Environment. 4. Hydrogen engine.
Text 1B. Diesel Engines vs Gas Engines - Reliability, Efficiency a) Read the text and answer the following questions. Are diesel engines as reliable as gas engines? Is a diesel engine more reliable than a gas engine? Does a diesel engine get better gas mileage than a gasoline engine? Why? What does the author recommend to avoid fuel gelling? 1. Diesel engines get better fuel economy simply because they do not need to burn as much fuel as a gas engine to get the same power. Diesel engines are also built heavier than a gas engine to sustain the added stress of the higher compression ratio. Diesel engines do not have an ignition system so you will never have to tune them up. Exhaust systems last longer because diesel fuel exhaust is not as corrosive a gasoline engine exhaust. It is not unusual to see a diesel engine with 400, 000, 500, 000 and I have even seen them go as much as 600, 000 miles. 2. The down side is they are fairly noisy. You will get the typical diesel clatter at idle, but that goes away off idle. At normal driving speeds they are as quiet as a gasoline engine. You won't get the same acceleration that you get from a gasoline engine. But a turbo diesel will get up and go fairly quickly. You will need to adjust your driving habits somewhat also. 3. As for maintenance, 3, 000 mile oil changes are a must! Diesel fuel is not as refined as gasoline and the oil will get dirtier than a gasoline engine. I recommend replacing air and fuel filters once a year. If you live in a cold climate, you will need to switch to a winter blend fuel to prevent fuel gelling. There are additives you can put in the fuel to help prevent this as well. I also recommend replacing glow plugs every two years as well. If temperatures drop below 10 degrees F, I would also recommend a block heater. This will insure cold weather starts, especially with the heavier grade oil that diesel engines require. ( 1560 characters) b) Complete the table.
Text 1C. Engines and Exhaust after Treatment Systems For Future Automotive Applications Render the following information according to this pattern: 1. The title of this text (information) is … 2. The text deals with …. 3. At the beginning the author explains (describes, introduces) ….. 4. Then the author pays attention to the issue of ( focuses on ) … 5. The author givesdetails concerning the …. 6. The advantages and disadvantages of …. are described and analyzed. 7. The improvements are proposed for … 8. The improved version of … is compared with (the conventional or analogue design). 9. The explanation is supported by (examples, results of experiments, pictures, graphs and diagrams). 10. In the end the author makes a conclusion that …... 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, NOX 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. ( 2029 characters) Unit 2 New Words Nouns
Verbs
Adjectives
Adverbs
Word Combinations
Glossary
Exercise 1. Match the pairs of synonyms: |
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