[4]P1 An Innovative Approach to Energy Conservation and Environmental Protection Utilizing Natural Gas in Municipal and other Transport Fleets

[4]P1 An Innovative Approach to Energy Conservation and Environmental Protection Utilizing Natural Gas in Municipal and other Transport Fleets

Medium and heavy duty vehicle fleets of trucks and buses are large users of diesel fuel energy. As the third world continues development, increased needs for transport will create a sharp increase on world fuel energy consumption and emissions.Natural gas is the most stable and promising alternative fuel which is not only widely available, but is also widely traded and is competitively priced. In fact, where pipeline gas is available, compressed natural gas (CNG) on board a vehicle, can be less costly than the equivalent as liquid fuel.Because natural gas mostly consists of methane, vehicle tail pipe hydrocarbon emissions are mostly nonreactive with very low atmospheric smog potential. Moreover, the slightly lower combustion temperature of natural gas results in lower NO, emissions at similar engine operating conditions. Because natural gas has a lower carbon content than diesel or gasoline, and requires less refining energy, the efficient use of natural gas will provide a substantial reduction of greenhouse gas emissions and results in lesser global warming potential.The development of the multipoint diesel dual fuel (MDDF) management system not only uses natural gas efficiently as in the diesel cycle, but also retains vehicle driveability and supports clean combustion which results in lower engine tail pipe emissions.When on board natural gas is available at a 35 to 50% lower cost than diesel fuel, and vehicle conversions may be depreciated in less than two years.Fuel efficiency of internal combustion engines powering vehicles, is largely a function of external forces acting upon the vehicle, the engine thermodynamic cycle and the load cycle of the vehicle.Diesel engines evolved for large trucks and buses because they are more energy efficient than gasoline engines, thus more cost effective in transportation and more competitive for commercial freight.Over the last 20 years the diesel engine tractor trailer unit has developed to the point that 50 litres/ 100 km of consumption is reduced to 35 litres/ 100 km due to many factors including reduction of drag coefficient, higher engine and transmission efficiencies and lighter vehicle weight '.However, today's engine building fraternity has set the clock back by more than twenty years, with the development and promotion of the fuel inefficient otto cycle CNG engine.Operators of fleet vehicles in load cycle sensitive applications have particularly been disappointed by the 30% higher capital cost, and also by the increased operating costs of the otto cycle CNG engine.Not knowing the nuances of th

1997-10-12

Badakhshan, A.

Mirosh, E.

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