Eco-friendly and economical Bosch CNG systems for commercial vehicles Dual-fuel operation with natural gas and diesel

· Engine control units and injection valves for CNG drives

· Up to 25 percent reduction in CO2 emissions

· Low operating costs and low emissions

Gasoline and diesel engines that can also be powered by natural gas are becoming increasingly important in the commercial-vehicle market. CNG (compressed natural gas) is particularly eco-friendly: compared with conventional diesel engines, CNG engines emit up to 25 percent less CO2. With its systems and components for CNG drives, Bosch is adding additional clean and resource-conserving products to its portfolio for commercial vehicles. CNG is also more cost-effective than conventional fuels, and CNG drives thus offer commercial-vehicle operators the benefit of lower operating costs.

CNG systems for medium and heavy commercial vehicles
Engines that are powered exclusively by natural gas – known as monovalent or mono-fuel drives – are used today primarily for urban traffic, in vehicles such as public buses and garbage collection trucks. In such vehicles, CNG is injected into the combustion chamber of a converted diesel engine at a pressure of some 6 bar. The engine is additionally equipped with spark plugs and ignition coils to ignite the mixture of air and natural gas. Monovalent engines are advanced enough today to comply with Euro IV emissions limits.

Dual-fuel, or bivalent, drives are also designed for medium and heavy commercial vehicles. Such drives allow up to 97 percent of the diesel fuel to be replaced by natural gas. In the dual-fuel method, diesel pilot injection ignites the CNG, making externally-supplied ignition unnecessary. Such dual-fuel engines offer greater independence in areas where the CNG infrastructure is incomplete, since they are fully able to run on diesel alone.

The tried-and-true, extremely compact Bosch NGI2 natural-gas injector can be used in both mono-fuel and dual-fuel systems. The same applies to the EGC4 und EGC10 control units, which control both conventional engine functions and the CNG injection valves, pressure regulation module, and tank shutoff valves and also monitor high- and low-pressure sensors. In dual-fuel operation, a communication interface connects the CNG control unit with a separate control unit that is used for conventional diesel injection.

CNG systems for light commercial vehicles
Bivalent systems are used in light commercial vehicles as well, where they run on a combination of natural gas and gasoline. The systems are based on modified gasoline engines. For the light-commercial-vehicle market, Bosch also offers the NGI2 natural-gas injector, which has been used successfully for years in passenger cars, and the NG Motronic bi-fuel engine control unit, which is based on the Motronic for gasoline injection. The NG Motronic makes it possible to switch between natural gas and gasoline even while vehicles are driving, without any interruption in torque. The use of a single control unit for gasoline injection and natural-gas injection cuts cost and makes integration into light commercial vehicles less complex.
The Bosch Group is a leading global supplier of technology and services. In the areas of automotive and industrial technology, consumer goods, and building technology, some 275,000 associates generated sales of 38.2 billion euros in fiscal 2009. The Bosch Group comprises Robert Bosch GmbH and its more than 300 subsidiaries and regional companies in over 60 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for growth. Each year, Bosch spends more than 3.5 billion euros for research and development, and applies for some 3,800 patents worldwide. With all its products and services, Bosch enhances the quality of life by providing solutions which are both innovative and beneficial.

The company was set up in Stuttgart in 1886 by Robert Bosch (1861-1942) as “Workshop for Precision Mechanics and Electrical Engineering.” The special ownership structure of Robert Bosch GmbH guarantees the entrepreneurial freedom of the Bosch Group, making it possible for the company to plan over the long term and to undertake significant up-front investments in the safeguarding of its future. Ninety-two percent of the share capital of Robert Bosch GmbH is held by Robert Bosch Stiftung GmbH, a charitable foundation. The majority of voting rights are held by Robert Bosch Industrietreuhand KG, an industrial trust. The entrepreneurial ownership functions are carried out by the trust. The remaining shares are held by the Bosch family and by Robert Bosch GmbH.

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PI7054 – September 2010