chapter  Chapter 4
17 Pages

Characteristics of Natural Gas Leaks in Bus Garages

WithPasquale M. Sforza, Herbert Fox

This chapter outlines a possible experimental scheme and shows the types of results that may be obtained. With the growing use of compressed natural gas (CNG) in fleet vehicles, it is of considerable importance to understand the characteristics of this fuel as it may leak into enclosed spaces forming a flammable plume. The chapter describes the behavior of a leaking CNG system in terms of both jet-like momentum-dominated, and plume-like buoyancy-dominated, effects. The effectiveness of current and proposed heating, ventilating, and air conditioning systems coupled to alarming devices, needs to be assessed to determine their potential in clearing the facility of leaks. As a consequence, the overall hazard of CNG vehicles was assessed to be not greater, and may actually be lower, than typical gasoline/diesel vehicles in a tunnel environment. Based on the model data, a number of locations which are representative of those studied would be identified and corresponding full-scale tests carried out.