Dynamic restriction mechanism for the upper limit of exhaust flow rates in the real-time sensing-based forced ventilation control of leaking hydrogen

•We developed a self-adjusting mechanism for the upper limit of exhaust flow rates.•The mechanism prevents hydrogen dispersion to the lower part of the test space.•We used a correlation between H2 concentration near the ceiling and leak rates.

We propose a novel control algorithm for hydrogen ventilation, utilizing a dynamic restriction mechanism for the upper limit of exhaust flow rates, extending the real-time sensing-based forced ventilation control algorithm of leaking hydrogen we proposed previously for a partially open space. This upper limit is determined using a correlation between hydrogen concentrations sampled near the ceiling, close to a leak source, and the upper boundary of the region of acceptable exhaust flow rates for various leak flow rates. We apply the algorithm to numerical simulations of hydrogen ventilation in a partially open space with low-height openings, varying leak flow rates and sensor arrangements. Results show that this algorithm works successfully.