Bosch CNG systems 15 to 20 percent reduction in CO2 emissions
2012-10-16 Source：www.chinabuses.org
Summarize：Lower operating costs and emissions
Engine control units and injection valves for CNG engines
Portfolio includes technology for monovalent and dual-fuel engines
www.chinabuses.org: Diesel and gasoline engines that can also run on compressed natural gas are gaining in significance in the global commercial-vehicle segment. Many countries are already promoting the introduction of CNG-powered vehicles.
This is because compressed natural gas (CNG) is especially eco-friendly. CNG engines emit 15 to 20 percent less CO2 than conventional diesel engines. Using natural gas also helps conserve oil reserves, while biogas opens up additional resources. Commercial-vehicle operators also benefit from the lower running cost of a CNG engine.
CNG systems for medium and heavy-duty commercial vehicles Monovalent engines, or engines that run exclusively on CNG, are currently mainly found in urban vehicles such as buses or garbage collection vehicles. In these vehicles, CNG is injected at a pressure of roughly seven bar into the intake manifold of a converted diesel engine. For the combustion of the air-natural gas mix, the engine is also fitted with spark plugs and ignition coils. Even today, these engines are Euro VI-compliant. The dual-fuel engine is also designed for medium and heavy-duty commercial vehicles. When using this system, CNG can be used instead of diesel as much as 90 percent of the time. In the process used here, a diesel injection system ignites the gas, thus obviating the need for an additional ignition system. Engines such as these offer greater independence in areas where the gas infrastructure is not so dense, since they can run purely on diesel without any restriction. Bosch’s dependable and extremely compact NG12 CNG injector can be used in both monovalent
and dual-fuel applications. This also applies to the EGC4 and EGC10 control units. In addition to conventional engine functions, they also control the gas injectors, the pressure regulation module, and the fuel tank shut-off valve, as well as high-pressure and low-pressure sensors. In dualfuel operation, a communication interface links the CNG control unit with a separate control unit for conventional diesel injection.
CNG systems for light commercial vehicles
In light commercial vehicle, bivalent (bifuel) systems are used, in this case combining CNG and gasoline. The systems are based on modified sparkignition engines. For this segment, Bosch offers the NG12 CNG injector, which has also worked reliably in the passenger-car segment for years now, and the NG-Motronic bifuel engine control unit, which is based on the Motronic for gasoline injection. This makes it possible to switch between natural gas and gasoline without interrupting torque, even when the vehicle is in motion. Combining the gasoline and CNG injection functions in one control unit saves costs, and reduces the effort needed to integrate the system in a light commercial vehicle.
Views:0Editor：Eric
Related China Bus News
editor@chinabuses.org
86-10-84933192;
