Spline Functions in Evaluation of Explosion Limit Curves for Gas Mixtures

Abstract

The paper discusses a new method to approximate the sometimes missing apex point of the explosion limit curves of flammable substances with diluents in air. The base of the new method is to vary the frame points of the co-monotonic splines using de Casteljau algorithm. We show several examples for flammable/inert/oxidising gas containing systems – selected by the program TRIANGLE – where the method was applied. Due to the definition of the frame of splines it can be stated that the new method never restricts the explosion range around the apex and shifts the explosion limit curve into the direction of higher inert gas concentrations. This means that the new method can correct the highly “cut down nose” of the co-monotonic splines and gives a safer explosion range of these systems.