(12c) Applicability of Currently Available Flare Radiation Models for Hydrogen and Syngas

The primary purpose of a flare
model is to provide a reasonably accurate prediction of radiant heat flux at
any point of interest around the flame, in order to define safe release
locations. In order to do this, a good flare model needs to provide reasonably
accurate prediction of the following critical flame parameters: flame length,
flame tilt, flame lift-off and radiant heat fraction including the impact of
wind and release orientation on these parameters. In addition, in order to make
a good prediction of heat flux at a point of interest, the model needs to
distribute the radiant heat along the flame and include the transmissivity
of the ambient air.

Industry standard models for vertical
flares include Chamberlain, API 521 and Brzustowski
& Sommer. 
These models were originally developed based primarily on hydrocarbon
data.  Several commercially available
consequence models allow the use of the these models for all flammable
materials and due to the lack of other options, these models are often applied
to hydrogen, syngas and other materials that are well outside the intended
scope of these models. A review has been performed to evaluate applicability of
these models and other available models, to hydrogen and syngas, including
comparison with limited published data. As a result of this review, a number of
significant concerns have been identified. This has led to initiation of a new
test programs to collect data specifically for hydrogen and syngas and
development of new models.