Global automotive supplier DENSO Corporation has developed a new diesel common rail (DCR) fuel injection system with the world’s highest* injection pressure of 2,500 bar. Based on DENSO’s research, the new system can help increase fuel efficiency by up to 3 percent while also reducing particulate matter (PM) by up to 50 percent and nitrogen oxides (NOx) by up to 8 percent. This is compared to DENSO’s previous generation system. The new DCR system will be launch-to-market later this year on passenger, commercial, agricultural and construction vehicles worldwide.
* For diesel common rail fuel injection systems composing injector, fuel pump and common rail.
“Our new diesel common rail system will help increase fuel efficiency and meet exhaust emissions standards that are becoming increasingly stringent around the world, particularly in Europe, Japan and the United States,” said Yukihiro Shinohara, executive director responsible for DENSO’s Diesel Engine Business Unit.
Improved design structure to decrease workload of fuel pump
- In a common rail system, a portion of the fuel delivered from the fuel pump to the injectors is used for purposes such as lubricating system components.
- That fuel is then returned back to the fuel tank, which puts an additional load on the fuel pump, instead of being injected into the engine combustion chambers.
- By improving the design structure of the injector, fuel pump, and common rail, DENSO significantly decreased the workload of the fuel pump by reducing the amount of fuel that was sent back to the fuel tank by about 90 percent.
Higher injection pressure
- To generate a higher fuel injection pressure, DENSO redesigned components and used new materials.
- These changes allowed the fuel to atomize into finer droplets, which improved fuel ignition and combustion efficiency, resulting in increased fuel economy and cleaner exhaust emissions.
- As automakers have limited space for component integration, DENSO was able to engineer and manufacture a fuel pump that is similar in size but more efficient than the previous system.
- DENSO was able to accomplish this by reducing the workload of the fuel pump as introduced previously.
History of Denso Diesel Common Rail Systems
- DENSO was the first in the world to commercialize diesel common rail systems in 1995.
- In 2002, DENSO offered an 1800 bar common rail system, the world’s highest injection pressure at the time.
- In 2008, DENSO released a 2,000 bar model into the market.
- In 2012, DENSO commercialized the world’s first engine control system called intelligent-Accuracy Refinement Technology (i-ART), in which the injectors have a built-in pressure sensor to measure fuel injection pressure in real time and control the fuel injection quantity and timing of each injector.
Future Denso developments
DENSO is working on development and commercialization of a 3,000 bar diesel common rail system. The company will continue to develop products and technologies that help improve the performance of diesel-powered vehicles to reduce its impact on the environment.
It seems that a race towards increased fuel pressure technology is on-going between tier 1 suppliers. Choice of pump and injector technologies is key in this race. Do you think piezoelectric injectors and 3 lobes pump will be able to overtake 3000 bar? Or any other technology will be able do so?