DENSO Develops a New Diesel Common Rail System With 2,500 Bar Injection Pressure
― Improved fuel efficiency and cleaner exhaust emissions ―
KARIYA (Japan) ―Global automotive supplier DENSO Corporation has developed a new diesel common rail (DCR) fuel injection system with an 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 launch to market 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 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.
First to Commercialize 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.
DENSO is working to develop and commercialize 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.
About Diesel Common Rail Systems:
- A diesel common rail system is the mainstream fuel injection system for diesel engines.
- The fuel, which is highly compressed by the fuel pump, is stored in an accumulator called a common rail.
- Then it is sprayed through the electrically controlled injectors into the combustion chambers.
- Storing highly compressed fuel in the common rail, not only further increases the pressure of the fuel, but also controls fuel injection pressure and timing without being effected by the engine’s rotation speed.
DENSO Corporation, headquartered in Kariya, Aichi prefecture, Japan, is a leading global automotive supplier of advanced technology, systems and components in the areas of thermal, powertrain control, electronics and information and safety. Its customers include all the world’s major carmakers. Worldwide, the company has more than 200 subsidiaries and affiliates in 36 countries and regions (including Japan) and employs more than 130,000 people. Consolidated global sales for the fiscal year ending March 31, 2013, totaled US$38.1 billion. Last fiscal year, DENSO spent 9.4 percent of its global consolidated sales on research and development. DENSO common stock is traded on the Tokyo and Nagoya stock exchanges. For more information, go to www.globaldenso.com, or visit our media website at www.densomediacenter.com.
Image: New Common Rail System (From the left: fuel pump, injector, and common rail)