Explosion Behaviour of 30% Hydrogen/70% Methane-Blended Fuels in a Weak Turbulent Environment

Abstract

In the present investigation the explosion characteristics of 30% H2/70% CH4-blended fuels have been experimentally studied in different turbulent environments. Some important indicators about the explosion characteristics, including maximum explosion pressure (pmax), explosion duration (tc), maximum rate of pressure rise ((dp/dt)max), deflagration index (KG), and fast burn period (tb) have been studied. Furthermore, the influences of turbulent intensity associated with the equivalence ratio on explosion characteristics have been compressively analysed. The results indicated that, with the increase of turbulent intensity (u’rms), the value of pmax will be correspondingly raised while the equivalent ratio (φ) corresponding to the peak value of pmax gradually changes from stoichiometric to 1.2. Based upon the value of pmax in laminar condition, the growth extent of pmax monotonically rises to u’rms, but under a same u’rms the growth extent of pmax first declines and then rises with the increase of φ in the rage of 0.6 to 1.2. Under a laminar environment, the peak value of (dp/dt)max is attained at φ = 1.0; although such a conclusion is maintained in the studied range of turbulent intensity, the difference on the value of (dp/dt)max between φ = 1.0 and φ = 1.2 is obviously reduced with the increase of u’rms. Meanwhile, from the variation of KG, it could be found that turbulence can raise the hazardous potential of disaster. With the increase of u’rms, both the values of tc and tb reduce, the quota of tb in the explosion performs a similar regulation, but the detailed variation extent is also controlled by u’rms.

Keywords

• hydrogen/methane mixtures
• turbulent explosion
• explosion pressure
• explosion duration
• deflagration index.