Classification of Changzhou Marine Turbochargers

To run fast, a car must have strong power. At present, the power system of automobiles can be roughly divided into two categories: natural intake system and turbocharged intake system. In European sports cars, except for BMW, which still insists on using naturally aspirated engines, other car companies have adopted turbocharging systems to improve the power performance of their vehicles. For example, Mercedes Benz sports cars use mechanical turbocharging systems, while Saab is the pioneer of turbocharging. In recent years, Japanese cars have also begun to extensively adopt turbocharging technology. The natural intake system is not equipped with any form of supercharger, but only uses the negative pressure generated by the downward piston to suck in the mixture. Although the natural intake system can achieve a larger horsepower output through a variable valve timing system, the power improvement is limited. To effectively increase the output power of the engine, adopting a turbocharging system can be said to be an effective way.

There are two common types of engine turbocharging systems: mechanical turbocharging and exhaust gas turbocharging.

Mechanical Boosting

The engine mechanically drives the supercharger to increase pressure, which is called mechanical supercharging. When the engine adopts mechanical turbocharging, the turbocharger is usually driven by the engine crankshaft through gears. Superchargers generally use centrifugal or Roots compressors, with some using screw compressors. In recent years, new types of mechanical vortex superchargers have also been adopted abroad. Because driving the compressor consumes a certain output power of the engine, the thermal efficiency of a turbocharged engine may not necessarily be improved, and sometimes it is even lower than that of a non turbocharged internal combustion engine. When selecting boost pressure, the first step is to ensure that the required average effective pressure can be achieved, and secondly, to achieve the lowest possible fuel consumption rate. Carrying these two requirements is often contradictory to mechanical boosting. If the pursuit of average effective pressure is pursued, it will inevitably lead to a decrease in mechanical efficiency and an increase in fuel consumption rate. Therefore, the selection of boost pressure value should seek a compromise solution between power and fuel consumption rate. The mechanical supercharging system is currently widely used in European cars. Due to the continuous operation of the turbocharged engine driven by the crankshaft, it does not produce a turbo lag phenomenon similar to turbocharging. Although mechanical turbocharging can only increase power output by about 10% to 20%, smoothness and continuity are unmatched by turbocharged engines.

Exhaust gas turbocharging

The use of engine exhaust gas energy to drive a turbocharger is called exhaust gas turbocharging (referred to as turbocharging), as shown in the figure, which is an exhaust gas turbocharging system. The characteristic of exhaust gas turbocharging is that there is no mechanical connection between the turbocharger and the engine. They are connected by an air path. Because the work consumed by the compressor is a portion of the energy recovered by the turbine from the exhaust gas, a turbocharged engine can not only increase the engine's power, but also improve its thermal efficiency and reduce fuel consumption. If the Turbo or T logo is seen at the rear of a sedan, it indicates that the engine used in the car is turbocharged. The turbocharger is actually an air compressor that uses the inertia of the exhaust gas discharged by the engine to drive the turbine, which in turn drives the coaxial impeller to compress the air sent by the air filter pipeline, allowing the air to be pressurized and enter the cylinder. When the engine speed increases, the exhaust gas discharge speed and turbine speed also increase synchronously, and the impeller compresses more air into the cylinder. The pressure and density of the air increase, which can burn more fuel. Correspondingly, increasing the amount of fuel and adjusting the engine speed can increase the output power of the engine.