Experimental study and prediction of liquid nitrogen pool evaporation process on concrete surface

The vaporization rate of pool boiling process of a liquid nitrogen spilled on concrete surface was investigated by a visual experiment platform. The boiling curve for liquid nitrogen on concrete cooling process was obtained. The shapes of bubbles in three typical boiling regimes were observed. Based on the experimental results, the coefficients of the empirical formulas for nuclear boiling and film boiling are modified, and the empirical formulas for boiling of liquid nitrogen-concrete surfaces are obtained. Combined with the calculation formula of the non-steady-state semi-infinite one-dimensional heat conduction temperature, a coupled calculation model for the heat transfer and vaporization process of liquid pool on the liquid nitrogen-concrete surface is proposed. Application of this model can better predict the quality of liquid nitrogen vaporization. •Visualization experiment of nitrogen pool evaporation on concrete surface was conducted.•The boiling mode transition process was observed by section pictures of liquid pool.•Boiling curves, MHF points and CHF points are obtained through experiments.•A coupled model for predicting the liquid nitrogen vaporization process is proposed.•The prediction error is reduced by the coupled model compared to the heat conduction model.