Determination of CF3CHFCF3 suppression effects on premixed hydrogen-methane deflagration via experiment and simulation

Abstract

To establish the suppression mechanism of CF3CHFCF3 on a premixed hydrogen-methane deflagration, the process was systematically explored by experimental and chemical kinetics simulation. The results show that CF3CHFCF3 has a beneficial suppression effect on the hydrogen-methane deflagration with 20 % H2 addition at the equivalence ratios of 0.8, 1.0, and 1.2 of premixed fuel. This suppression process is divided into three phases. First, there is the physical inhibition phase. The addition of CF3CHFCF3 acts as dilution and cooling. Then, there was the chemical thermal promotion phase. The fluorides produced by the pyrolysis of CF3CHFCF3, such as C3F7, CF3CHF, C3F7O, and CF3, release an enormous amount of heat while participating in the reaction of the combustion system, which promotes the forward chain reaction of the combustion system. Finally, there is the chemical inhibition phase. Fluorides consume an immense number of active radicals and generate unreactive radicals to inhibit hydrogen-methane-air deflagration. Furthermore, the accumulated unreactive gases, such as HF and CO2, become a new third-body dilution reactant concentration. This study provides insight into the process of CF3CHFCF3 inhibition and renders theoretical guidance for the explosion protection of hythane.