Internal diesel combustion engines have been developing for more than one hundred years and have now been very well developed because of unceasing improvement. Due to its high heat efficiency, adaptability and wide power range, diesel is widely used in industry, agriculture, transport, as well as national defense. So here we briefly provide some introduction on its history of development, use and basic knowledge.
Generally speaking, diesel combustion engine belongs to the category of engines whose fuels combust within the machine. It consists of diesel engine which has to-and-fro moving pistons, gas turbine, and jet engine e.tc. Outer combustion engine, a kind of machine whose fuels combust outside; this includes steam engine, nuclear-powered equipment which are mainly used in ocean liners and steam turbines.
Gas turbines and jet engines are nearly the only power equipments in use in aero power equipment. Yet gas turbines have notgenerally been very extensively used in marine and land applications. Although it has a series of merits such as little weight, small dimension, good torque quality, and little vibration and noxious gases emission e.t.c, gas turbine has more distinct characteristics such as low heat efficiency, high ratio of fuel combustion for example. It has improved during high power whereas cannot be compared with diesel engine during low power.
Petrol engine is widely used in small passenger cars for its merits of high output per liter, low noise, little vibration and quick response to load changes etc. Recently there is a large amount of petrol engine output because of the large quantities of small passenger cars. Besides, petrol engine is also used in camions, motorboats and pint-sized agriculture and forestry machines.Yet it can not compete with diesel engine in other economic fields due to higher fuel price and higher fuel consumption ratio,compared with that of diesel engine.
As regarding inland shipping and engineering machinery, diesel engine is the only engine relied upon for power. Steam engines have been eliminated abroad in locomotives and in China, production of steam engines have already been stopped and replaced by diesel engines and electric engines. Furthermore, the power output capacities of diesel engines have been on the increase; now a single machine capacity can generally achieve 3000kw and 4600kw at most.
Recently, many countries focus their attention on developing their nuclear powered and gas turbine powered equipment in naval ships for military use. But in light naval ships, the use of diesel engines still remains dominant. They are also the main power source in marine naval ships such as submarine hunters, missile yachts, mosquito boats, coastguard cutters,minesweepers, landing crafts and most routine submarines. Only a few surface submarines use diesel engine-gas turbine combination powered equipment.
Diesel engine is also extensively used in the mobile electric station and spare electric station. With the development of high powered and medium-speed diesel engine, it is already generally being used in fixed power stations. Now high-powered and medium-speed diesel engines are being used economically in power stations with generating capacity of 100000kw, and soon the generating capacity will reach 200000kw.
The output of diesel engine all over the world is quite large and keeps increasingly growing due to its wide use. It occupies avery important place in the economy and national defense industry and will play a vital role in the four modernizations in China.