Quantitative detection of hydrogen peroxide in an HCCI engine using photofragmentation laser-induced fluorescence

Abstract

A photofragmentation laser-induced fluorescence (PF-LIF) technique was applied to an HCCI engine for hydrogen peroxide (H2O2) measurements. A pump–probe strategy was adopted with the pump laser (266nm) photolyzing H2O2, and with the probe laser (283nm) detecting the generated OH photofragments. An on-line calibration process was performed by introducing a known amount of vaporized H2O2/water solution into the engine cylinder. Crank-angle resolved mass fractions of H2O2 were obtained, and for the first time, single-shot imaging of H2O2 was realized in the HCCI engine. It has also been verified that the PF-LIF signal originates mainly from H2O2 with a smaller interference from HO2. The crank-angle resolved experimental data were compared to mass fractions calculated with the software package Digital Analysis of Reaction Systems (DARS). The calculated H2O2 profile agrees well with the experimental results regarding mass fraction level, while the shapes of the profiles deviate slightly. Calculated mass fractions of HO2 indicate that interfering signal contributions from HO2 is the major reason for the deviation.