Effect of non-condensable gas on thermal stratification and flow patterns in suppression pool

•Effect of the non-condensable gas on the direct contact condensation in suppression pool was studied.•Both particle image velocimetry and high speed camera are used for the experiments.•Influence of non-condensable gas on thermal stratification, condensation behavior, and velocity was obtained. This work analyzes the effect of the non-condensable gas on the direct contact condensation in suppression pool with thermal stratification. Both the Particle Image Velocimetry (PIV) system and high speed camera are used for the experiments. The influences of the non-condensable gas on the thermal stratification, the condensation behavior, and the velocity field are obtained in detail through the experiments. What is more, the experimental quantitative results about the direct contact condensation of vapor mixing with the non-condensable gas in the suppression pool would be used as benchmarking for the CFD simulation of relevant phenomena.