The highly combustible nature of hydrogen poses a great hazard, creating a number of problems with its safety and handling. As a part of safety studies related to the use of hydrogen in a confined environment, it is extremely important to have a good knowledge of the dispersion mechanism.

The present work investigates the concentration field and flammability envelope from a small scale leak. The hydrogen is released into a 0.47 m × 0.33 m x 0.20 m enclosure designed as a 1/15 – scale model of a room in a nuclear facility. The performed tests evaluates the influence of the initial conditions at the leakage source on the dispersion and mixing characteristics in a confined environment. The role of the leak location and the presence of obstacles, are also analyzed. Throughout the test, during the release and the subsequent dispersion phase, temporal profiles of hydrogen concentration are measured using thermal conductivity gauges within the enclosure. In addition, the BOS (Background Oriented Schlieren) technique is used to visualise the cloud evolution inside the enclosure. These instruments allow the observation and quantification of the stratification effects.

氢的高度易燃性构成了极大的危害，在其安全性和操作性方面造成了许多问题。作为与在密闭环境中使用氢气有关的安全性研究的一部分，对分散机理有充分的了解非常重要。

本工作调查了小范围泄漏引起的浓度场和可燃性范围。氢气被释放到一个0.47 m×0.33 mx 0.20 m的外壳中，该外壳被设计为核设施房间的1/15比例模型。进行的测试评估了泄漏源的初始条件对密闭环境中分散和混合特性的影响。还分析了泄漏位置和障碍物存在的作用。在整个测试过程中，在释放和随后的分散阶段中，使用外壳内的热导仪测量氢浓度的时间分布。此外，BOS（背景定向Schlieren）技术用于可视化机箱内部的云演变。