America and diesel engine
Diesel engines are not only CO2 emissions has been far ahead of gasoline engine, and the sulphur content of fuels in the near future will be less than a gasoline engine. Over the years, automobile exhaust are believed to have triggered one of the most important causes of the greenhouse effect. While the United States and are considered CO2 emissions, China's two largest countries. According to the survey, 2004 European car market, nearly half of the new cars is a new type of green diesel engine. Cars on roads in the United States, but only 1% is a diesel engine. The reason is simple, American consumers have the lowest gasoline prices in the world. But now the United States market of gasoline prices near historical highs, which forced American consumers to turn to focus on economy cars that will save them money.
Two years ago, only two of the cars on the market in the United States using a diesel-powered engine. Today, with rising gasoline prices, there are 13 diesel car in the American car market, and by 2006 will have 6 new car market. When the types of cars with diesel engines will reach nearly 20. President Bush signed on diesel engine file points the way forward for the future of diesel vehicles. American policymakers and consumers have found that diesel is a good choice. Diesel vehicles for China is also a good choice. In the condition of market mechanisms, using a diesel-engine car will have a more promising future. History of diesel engines in 1905, German diesel invented the diesel engine; 1976 Volkswagen Golf car in the first place have diesel engines; 1989 Volkswagen Golf diesel vehicles get "low emission car" in the title; In 1990, Volkswagen introduced a turbocharged, direct-injection diesel engine for the first time, Volkswagen diesel power technology development and application has been at the forefront of the world;
In 1993, developed a four-cylinder turbocharged direct injection diesel engines (TDI); In 1995, developing naturally aspirated direct injection (SDI) diesel engine; In 1995, the variable geometry turbocharger; In 1998, developed a pump nozzle technology; In 1999, developed a 3-litre road car is diesel-powered future mainstream technologies. Diesel-powered future will create a bright new economy, Germany shocked the world in mass one-liter car is born, this concept car diesel fuel consumption per hundred kilometers for a record 0. 99----the most fuel-efficient cars in the world. Natural aspirated engine uses an aluminum single cylinder diesel engine uses advanced high-pressure direct injection technology, displacement of 0. 3 litres; In 2002, Faw-Volkswagen took the lead in the Jetta SDI was launched in China market; In 2004, Faw-VW TDI technology is introduced, leading the era of China's new power. Diesel engine working principle of working process of diesel engines and gasoline engines, each working cycle through intake, compression, power, exhaust four-stroke. However, because the diesel fuel is diesel, its viscosity than gasoline, and not easily evaporate, and the autoignition temperature is lower than that of petrol, flammable mixture formation and ignition gasoline engine is different. Diesel engine breathe pure air in the intake stroke. In the compression stroke when they approach the end of diesel injection pump to increase the pressure to 10MPa or more through the injector into the cylinder, in a short period of time and high temperature of the compressed air mixed to form a combustible mixture. Due to the diesel engine compression ratio (usually 16-22), so at the end of the compressed air in the cylinder pressure can be up to 3. 5-4. 5MPa, at temperatures up to 750-1000K (mixture of gasoline engines at this time pressure is 0. 6-1. 2MPa, temperatures up to 600-700K), much higher than the ignition temperature of diesel fuel. So after the diesel is injected into the cylinder, mixed with air in a very short time firing on their own immediately after burning. Sharp rise in pressure in the cylinder to the 6-9MPa, the temperature rises to 2000-2500K. High pressure gas, driven by downward movement of the piston and crankshaft driven work exhaust as exhaust pipe discharges into the atmosphere. Ordinary diesel engine is driven by the engine camshaft by means of high pressure fuel pump diesel into the cylinder Chamber. This method of fuel supply to the engine speed changes, do not at all engine speeds the optimal amount of oil. And now has become more and more common use of electronically controlled diesel engine with common rail injection systems can be used to solve this problem.
Common rail fuel supply system by high pressure oil pump, public supply pipe, injectors, electronic control units (ECU) and a number of pressure sensors, each injector on the system through their pipe and connected to the public supply line, public supply line to the fuel injector to the hydraulic accumulator. When high pressure oil pump to high pressure fuel delivery to the public for tubing, high pressure oil pump and pressure sensor and ECU closed loop, common fuel supply pipe hydraulic for precise control and completely change the supplied pressure changes with engine speed. Its main features are the following three aspects: 1, injection timing and fuel metering completely separate, injection pressure and injection processes controlled by the ECU in due course. 2, can be based on work conditions to adjust the fuel injection pressure of each cylinder of the engine, fuel injection point, duration, to pursue fuel optimal control points. 3, can achieve very high injection pressure, the pilot injection and diesel. Compared to the gasoline engine, diesel engine fuel consumption rate is low (average 30% lower than gasoline engines), and diesel prices low, so fuel economy better; much lower speeds than gasoline engines and diesel engines, and greater torque than gasoline engines, but its great quality, great noise at work, manufacturing and high maintenance costs, and poor emissions than gasoline engines. But with the development of modern technology, diesel engines of these disadvantages are gradually being overcome, not limousines are now are beginning to use diesel engines.
Source: http://www.mesmaxuk.com/
