掺氢天然气喷射火燃烧特性实验研究

Experimental study on the combustion characteristics of hydrogen-blended natural gas jet fires

能源结构转型初期,天然气管道掺氢是一种有效的输氢方式,然而掺氢会提高气体活跃性,在管道泄漏的情况下增加火灾风险。在压力200~800 Pa和掺氢比0~50%条件下开展了掺氢天然气水平喷射火实验研究,以预测和评估其潜在的火灾风险。实验结果表明:掺氢后火焰温度升高,最大温差为113℃;在高压下当掺氢比>10%时,火焰温度分布发生明显变化;火焰的推举距离随压力增加而增大,随掺氢比增加而减小;当高压下掺氢比<10%时,掺氢对火焰尺寸影响较小,当掺氢比增加到50%时,火焰长度的最大降幅为13.7%。此外,提出了掺氢天然气火焰长度无量纲预测模型。研究结果可为掺氢天然气管道事故后果及火灾风险评估提供必要的数据支持和理论基础。

Blending hydrogen into natural gas serves as an efficient transportation method during the early phases of energy structure transformation.However,adding hydrogen elevates the gas activity,thereby increases the fire hazard in the event of a pipeline leakage.To predict and assess the potential fire risks associated with hydrogen-blended natural gas,we undertook horizontal jet fire experiments under varied conditions,spanning pressures from 200 to 800 Pa and hydrogen blend ratios from 0 to 50%.Our findings suggest that the flame temperature rises after hydrogen blending,with a peak range of temperature of 113℃.At elevated pressures,the flame temperature distribution undergoes notable changes once the hydrogen blend ratio surpasses 10%under high pressure.The lift-off distance of flame increases with pressure increase but diminishes with a higher hydrogen blend ratio.With a hydrogen blend ratio below 10%under high pressure,its impact on flame size remains negligible.However,at a 50%blend ratio,there s a maximum flame length reduction of 13.7%.Furthermore,we introduce a dimensionless flame length prediction model tailored for hydrogen-blended natural gas.This research outcomes furnish essential data and a theoretical basis for evaluating fire risks and consequences of incidents relating to hydrogen-blended natural gas pipelines.