Diesel generator pressurization system and method
Diesel generator charging technology is to improve the density of the air intake, increase the intake air per cycle, multi-injection to increase the average effective pressure on the engine power output is increased. The use of booster can not only increase the power of the diesel engine can also improve the thermal efficiency, improve the economy, reduce emissions of harmful ingredients, reduce noise.
Supercharged diesel generator mode
The driving source of the booster of the type of energy used, pressure can be divided into the following four methods.
1 Supercharger System
Supercharged diesel engine turbocharger system through the gears, belts, chains and other gear drive, give it away after the compressed air cylinder, as shown in Figure 2.31. Using centrifugal supercharger or Roots-type compressor.Features supercharger system are: diesel engine exhaust back pressure does not increase, but the drive you want to install a device on the engine, but also the effective power consumption of a diesel engine, the diesel's economy declined. But it can improve low-speed torque characteristics of the diesel engine. In addition, the mechanical supercharger engine is easy to match with the structure more compact, mechanical response is relatively fast.Supercharger system used for the small diesel engine, turbocharger pressure is generally not more than ((0. 15-0.17) MPa. When the boost pressure increased, consumption-driven compressor merits great cause decreased mechanical efficiency, economy worse.
2 exhaust turbocharger system
From the exhaust gas turbocharger turbine and compressor, as shown in 2.32 below. The introduction of diesel exhausts turbine exhaust gases contain child can use to promote the turbine wheel to rotate and drive the compressor wheel mounted coaxially with their work, fresh air cylinder supercharged backward people in the compressor. Diesel exhaust gas turbocharger with no mechanical contact, and simple structure, reliable work.
After the diesel engine exhaust gas turbocharger, since the thermal efficiency and the mechanical efficiency, fuel consumption rate decreased, improving the economy of the diesel engine; while weight increase due to the increase is much smaller than its power, reducing the weight of the diesel power unit, such reduced weight and power ratio increased, and secondly, the diesel engine in the larger lower air ratio over t the case, more complete combustion, exhaust pollution has been improved. Therefore, exhaust gas turbocharger system has been widely used.
3 composite pressurization system
On some engines, in addition to the application exhaust gas turbocharger, supercharger also apply, such pressurization system called composite pressurized system (Figure 2.33). Some of the large two-stroke diesel engine, in order to ensure the scavenging pressure and the low-speed and low-load starting is still required, the need to use complex pressurization system. Combined Charging System has two basic forms: one is a series turbocharger systems, diesel exhaust into the exhaust gas turbine driven centrifugal compressor to increase the air pressure, and then give it away again supercharger boost to further improve diesel air pressure backward people; after the other is parallel pressurization system, exhaust gas turbocharger and supercharger air pressure increase, respectively, into the diesel engine.
4 air-wave supercharger system
Air wave supercharger has a special shape. Shaped rotor 3 by 4 diesel engine crankshaft via the belt drive. In the rotor 3 in the exhaust gas discharged from the diesel engine direct contact with air, the air using the exhaust gas pressure wave is compressed to increase the intake pressure. Simple pressure wave supercharger structure, easy to process, temperature is not high, no heat-resistant material, and without cooling. Compared with turbo, good low-speed torque characteristics, but bulky, high noise levels, the installation location subject to certain restrictions.
Such pressurization system need to be further developed to study, to get practical application.
Four kinds of booster mode, the most widely used is the exhaust gas turbocharger systems and exhaust gas turbocharger.