DIESEL ENGINE OPERATING PRINCIPLE
A diesel engine is an internal combustion engine that uses the heat of
compression to initiate ignition and burns the fuel that has been injected into
the combustion chamber. The engine was
developed by German inventor Rudolf Diesel in 1893.
Diesel engines are manufactured in two-stroke and four-stroke versions.
They were originally used as a more efficient replacement for stationary steam
engines. Since the 1910s they have been used in submarines and ships. Use in
locomotives, trucks, heavy equipment and electric generating plants followed
later. The world's largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C
Common Rail marine diesel of about 84,420 kW (113,210 hp) @ 102 rpm output.
The diesel internal combustion engine differs from the gasoline powered
Otto cycle by using highly compressed hot air to ignite the fuel rather than
using a spark plug.
In the true diesel engine, only air is initially introduced into the
combustion chamber. The air is then compressed. The high compression heats the
air to 550 °C. At about the top of the compression stroke, fuel is injected
directly into the compressed air in the combustion chamber. This may be into a
void in the top of the piston or a pre-chamber depending upon the design of the
engine. The vapour is then ignited by the heat from the compressed air in the
combustion. The rapid expansion of combustion gases then drives the piston
downward, supplying power to the crankshaft.
Diesel engines have several advantages over other internal combustion
engines:
They burn less fuel than a petrol engine performing the same work.
They have no high voltage electrical ignition system, resulting in high
reliability and easy adaptation to damp environments. The absence of coils,
spark plug wires, etc., also eliminates a source of radio frequency emissions
which can interfere with navigation and communication equipment, which is
especially important in marine and aircraft applications.
The life of a diesel engine is generally about twice as long as that of
a petrol engine due to the increased strength of parts used. Diesel fuel has
better lubrication properties than petrol as well.
Diesel fuel is considered safer than petrol in many applications.
Although diesel fuel will burn in open air using a wick, it will not explode
and does not release a large amount of flammable vapor. The low vapor pressure
of diesel is especially advantageous in marine applications, where the
accumulation of explosive fuel-air mixtures is a particular hazard. For the
same reason, diesel engines are immune to vapor lock. They generate less waste
heat in cooling and exhaust.
Diesel engines can accept super- or turbo-charging pressure without any
natural limit, constrained only by the strength of engine components. This is
unlike petrol engines, which inevitably suffer detonation at higher pressure.
The carbon
monoxide content of the exhaust is minimal, therefore diesel engines are used
in underground mines.
I. Read the text and translate the following sentances into English.
1. Дизельний двигун був винайдений німецьким винахідником Рудольфом Дизелем в 1893 році.
2. З 1910 року дизельні двигуни використовуються на суднах і підводних човнах.
3. Найбільший дизельний двигун в світі на даний момент - це морський дизель потужністю 84.420 кВт.
4. Дизельні двигуни мають кілька переваг над бензиновими двигунами.
5. Дизельні двигуни спалюють менше палива, ніж бензинові двигуни.
6. Дизельні двигуни мають високу надійність і легко адаптуються до вологого навколишнього середовища.
7. Вміст чадного газу у вихлопі дизельного двигуна мінімальний.
8. Найпотужніші двигуни в світі - це двотактні дизелі.
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