However, the 477 is a marine mainframe, which is considered as a small mainframe in China, and should only be considered as general in the industry; Moreover, the shipbuilding industry is greatly influenced by the international situation and is very sensitive. If the economic situation is not good, it will be greatly affected immediately. At present, the market situation of shipbuilding industry is quite depressed.
Note: diesel fuel is mainly diesel, and high-speed diesel engines usually use light diesel; Light diesel oil or heavy diesel oil for medium and low speed diesel engines. Diesel engine uses fuel injection pump and injector to inject fuel into cylinder at high pressure, and the sprayed fuel is atomized and mixed with air for combustion. Therefore, diesel engines can use heavy or inferior fuels with poor volatility, such as crude oil and residual oil.
When burning crude oil and residual oil, in addition to filtering out impurities and moisture, the oil supply system should be preheated and insulated to reduce viscosity and facilitate transportation and injection. If a suitable combustion chamber is used, diesel engines can also burn light fuels, such as ethanol, gasoline and methanol.
In order to improve the ignitability of light fuel, additives can be added to increase cetane number or mixed with diesel oil. Some gas fuels, such as natural gas, liquefied petroleum gas, biogas, producer gas, etc., can also be used as diesel fuel, but at this time, gas fuels are usually the main fuel, and a small amount of diesel oil is used for ignition. This kind of engine is called dual-fuel internal combustion engine.