A car must have a strong drive to run fast. At present, the power system of the automobile can be divided into two categories: natural inlet system and pressurized intake system. In the European sports car, in addition to the BMW Motor Company still insists on the use of natural air intake engine, the other car companies in order to enhance the vehicle's dynamic performance, have adopted a supercharged system, such as: Mercedes-Benz sports car use of mechanical pressurization system, Saab car is turbocharged pedigree. In recent years, Japanese cars have also begun to use turbo-boosting technology. The natural intake system does not have any form of supercharger installed, but it uses the negative pressure generated by the piston to suck in the mixture. Although the natural intake system can get a larger horsepower output through a variable valve timing system, the power boost is limited. In order to effectively increase the output power of the engine, it is the most effective way to use the turbocharging system.
The most common engine pressurization system has two kinds of mechanical pressurization and exhaust gas turbo pressurization.
The engine mechanically drives the supercharger to pressurize, called the mechanical pressurization. When the engine is mechanically pressurized, the engine crankshaft is usually driven by a gear drive supercharger. Turbocharger general use centrifugal or roots compressor, individual use of screw compressors. In recent years, a new type of mechanical vortex supercharger has been used in foreign countries. Because the driving compressor consumes a certain output power of the engine, the thermal efficiency of the supercharged engine is not necessarily improved, sometimes it is lower than the non pressurized internal combustion engine. When choosing pressurization pressure, first of all to ensure that the required average effective pressure, the secondary access to the lowest possible fuel consumption rate. These two requirements are often contradictory to mechanical pressurization. If the average effective pressure is pursued, the mechanical efficiency is reduced and the fuel consumption rate is increased. Therefore, the selection of pressurization pressure value should seek the best compromise between power and fuel consumption rate. The mechanical pressurization system is now widely used in European cars. As the supercharged supercharger is continuously running under the crankshaft, it is not moving to produce a turbo-lag phenomenon such as turbocharging. Although the mechanical boost can only increase the power output of about 10% 20%, the smooth continuity is less than the turbocharged engine.
Exhaust gas Turbo
The use of engine exhaust energy to drive the turbocharger, known as the exhaust turbo (Turbo Boost), as shown in the exhaust gas turbo-charging system. The exhaust gas turbo is characterized by a mechanical connection between the turbocharger and the engine. They are connected by a gas path. Because the work of the compressor is a part of the energy that the turbine recycles from the exhaust gas, the turbocharged engine can not only increase the engine's power, but also increase its thermal efficiency and reduce the fuel consumption rate. If the logo of Turbo or T is seen at the rear of the car, it indicates that the engine used is turbocharged. Turbocharger is actually an air compressor, it is the use of engine exhaust gas inertia to promote the turbine, the turbine and drive the coaxial impeller compressed by air filter pipe sent air, so that the air pressurized into the cylinder. When the engine speed increases, the exhaust gas discharge speed and the turbine speed also synchronously improve, the impeller compressed more air into the cylinder, the air pressure and density increase can burn more fuel, the corresponding increase in oil volume and adjust the engine speed, you can increase the output power of the engine.