Cloud Explosions - Sample Problems

The methods described in this chapter are meant for practical application background information is given in Chapter 4. If a quantity of fuel is accidentally released, it will mix with air, and a flammable vapor cloud may result. If the flammable vapor meets an ignition source, it will be consumed by a combustion process which, under certain conditions, may develop explosive intensity and blast. 

The explosion hazard of a vapor cloud can be quantifled in terms of its explosive power after ignition. The explosive power of a vapor cloud can be expressed as an equivalent explosive charge (TNT or fuel-air) whose blast characteristics, that is, the distribution of blast-wave properties in the charge s vicinity, are known. 

Several methods of quantiflcation are described in Chapter 4. Chapter 4 discusses in detail two fundamental approaches to quantiflcation of explosive power, together with advantages and disadvantages. In addition, there are two different blast models, each of which has certain benefits. This chapter offers guidance on their use. Application of each method is described in Section 7.2. and demonstrated in Section 7.3. Section 7.1. offers some guidance on choosing an approach and a blast model. 

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Chapters 7, 8, and 9 demonstrate the consequence modeling techniques for vapor cloud explosions, BLEVEs, and flash fires, respectively, by presenting sample problems. These problems contain sufficient detail to allow an engineer to use the methods presented to evaluate specific hazards. 

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