Diffusion behavior assessment of underwater active venting for combustible gases: An experimental study with helium instead of hydrogen

In the active venting process of the burn pond, the hydrogen diffusion behavior underwater directly affects their uniformity on the water surface and the stability of the safety burning. A series of visualization experiments are conducted to assess the influence of disposal structure, flow rate, and water seal depth on the diffusion area and fountain height for rising plume formation. Helium is used as a substitute for hydrogen in the experiments. The study demonstrates that the plume structure is notably smaller in bubble cap mode compared to the nozzle mode, regardless of the conditions. This mode minimizes water surface fluctuation efficiently, making it ideal for constructing a disposal-array burn pond with multiple bubble cap units. Additionally, through dimensionless analysis, the study quantifies the parameters related to water surface stability with various venting conditions, thus establishing a foundation for the underwater active venting of hydrogen and other combustible gases.