|Bosch’s CRSN3-25 offers injection pressure of up to 2,500 bar. Click to enlarge.|
As it outlined in 2010, Bosch has increased the maximum injection pressure of its CRSN3-25 injection system for medium- and heavy-duty commercial vehicles to 2,500 bar. The aim is to help meet more stringent emissions standards such as US 10 and Euro VI; higher injection pressures help lower fuel consumption and emissions.
With the CRSN3-25, up to seven individual injections are possible. This increases flexibility in terms of engine design, promotes lower exhaust and fuel consumption levels, and results in even quieter operation. Due to a software learning feature, the amount of fuel injected can be adjusted. This makes it possible to meet strict emission standards over the entire vehicle life cycle, even when annual mileage is high.
The modular CRSN3 injection system is designed for operation with diverse injection pumps depending on customer specifications and needs. It can be used in diesel engines with up to 16 cylinders, as well as in on- and off-highway applications. This covers short and long-haul road travel, as well as construction machinery, tractors, and maritime applications.
For heavy-duty vehicles, a new generation of the CPN5 high-pressure pump can be applied. In addition to generating pressures of up to 2,500 bar, it is especially compact, robust, and lightweight. The pump has a service life of 1.6 million kilometers and 15,000 operating hours in off-highway applications. Its service life is thus longer than that of the average vehicle.
With its pressure-balanced interior, the innovative injector concept offers an especially high level of hydraulic efficiency, according to Bosch. Since its exterior geometry remains unchanged, the injector used in the CRSN3-25 is compatible with its predecessor system.
Another advantage of the new system is an improved diagnostic capability. Due to an integrated pressure limiter, a comprehensive system check can be carried out when the vehicle is being serviced.
Combined with exhaust gas recirculation and SCR systems, Bosch high-pressure injection systems make a significant contribution to reducing fuel consumption and nitrogen oxides. However, the combustion processes that this involves require high injection pressures in order to prevent a rise in particulate raw emissions.
Bosch injection systems with even higher injection pressures are currently in the development pipeline. The company is also working on additional systems to reduce fuel consumption and emissions. Ss one example, Bosch has developed CNG injection systems for commercial vehicles as well as the Denoxtronic and Departronic exhaust gas treatment systems. The company is also active in the areas of powertrain hybridization and waste heat recovery systems.
Automotive Technology is the largest Bosch Group business sector. Its sales came to €30.4 billion (US$37.7 billion), or 59% of total group sales, in fiscal 2011.