Photoacoustic dual-gas sensor for simultaneous detection of hydrogen and water vapor

Hydrogen (H2) is an important energy carrier, however, it can be hazardous owing to the risks involved with boring and explosion with colorless flames. By detecting the concentrations of H2 and vapor water (H2O) in real time, such risks can be prevented in advanced. In this study, a sensor system is developed based on photoacoustic spectroscopy using an H-type photoacoustic cell (PAC). Further, the time division multiplexing technique is used in a specific scanning period to realize dual-gas simultaneous detection. The dimensions of the PAC are optimized (inner volume: 1.8 cm3) and N-th characteristic frequencies are simulated through multiphysics simulation in COMSOL software. The optimized PAC is applied in the system and experiments of simultaneous dual gases detection are performed. The detection results show that the sensor's response time is 0.51 s and the recovery time is 0.38 s, and the minimal detection limit of H2 is 138.69 ppm and H2O can reach 3.70 ppm.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.