JAPAN: Denso develops new diesel common rail system
Denso says it has developed a new diesel common rail (DCR) fuel injection system with the world's highest injection pressure of 2,500 bar.
Based on its research, the company claims the new system can help increase fuel efficiency by up to 3% while also reducing particulate matter (PM) by up to 50% and nitrogen oxides (NOx) by up to 8% (compared to Denso's previous generation system).
The new DCR system will launch later this year on passenger, commercial, agricultural and construction vehicles worldwide.
"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 US," 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%.
Higher injection pressure:
- To generate a higher fuel injection pressure, Denso redesigned components and used new materials.
- These changes allowed the fuel to atomise 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.
- First to commercialise diesel common rail systems.
- Denso was the first in the world to commercialise diesel common rail systems in 1995.
- In 2002, Denso offered an 1,800 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 commercialised 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.
Denso is working to develop and commercialise 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.