Effect of distance of cylinder and release pressure on the hydrogen jet flame temperature distribution induced by impingement of ignited release of hydrogen

Hydrogen is clean, green, and environmentally friendly, and it can be beneficial in solving the climate problem of global warming. However, hydrogen is flammable and explosive, and it is crucial to study the characteristics of hydrogen jet flame. At present, the temperature decay law of hydrogen jet flame after hitting the cylinder is not clear. In this paper, the temperature distribution of the jet flame formed on the surface of the cylinder after hydrogen leakage was experimentally investigated at a nozzle diameter of 1.50 mm, a leakage pressure of 0.15–0.30 MPa, and a nozzle distance of 0.20–0.40 m. The ground is approximately 0.16 m from the lower surface of the cylinder. The results of the study showed that the flame expansion region after hitting the cylinder and the maximum over-temperature increases with increasing initial pressure and decreasing cylinder-to-nozzle distance. In the longitudinal direction along the cylinder, relationship between dimensionless distance and dimensionless over-temperature satisfying Gaussian distribution. And when the longitudinal distance is greater than 0.10 m, the over-temperature increases with the distance from the cylinder to the nozzle. In the vertical direction, an exponential relationship is satisfied between dimensionless distance and dimensionless over-temperature. These temperature prediction models are only applicable to the boundary conditions in the paper. The results of the study contribute to the improvement of hydrogen safety.