Ignition and transition to detonation under chain-branching kinetics

链支化动力学下的点火和爆炸转变

• 批准号: 137983-2009
• 负责人: Bauwens, Luc
• 金额: $ 3.42万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=513731
• 关键词: Ignition; transition; detonation; under; chain

Hydrogen is an attractive automotive fuel because it burns without releasing CO2 or other greenhouse gases, and because it is the fuel of choice for fuel cells. Hydrogen production from hydro power or wind energy is carbon-neutral. However, because hydrogen has a markedly different behaviour when compared with hydrocarbon fuels, there are significant safety issues that need to be resolved before widespread hydrogen storage and distribution facilities are allowed in close contact with populated areas. Likewise, there are safety issues associated with hydrogen storage in vehicles in tunnels and public garages. Because hydrogen is very light and buoyant, outdoors installations can be made safe by ensuring that there is enough distance around where the public is not allowed. However, in enclosed environments, serious issues remain, mostly associated with the risk of detonation, which hydrogen is much more prone to than other fuels. Detonation is the most violent form of combustion, in which combustion rides on a shock wave which it also supports. Thus detonation waves travel at high supersonic speeds as long as they encounter combustible mixture, and they entail a pressure increase usually in the tens of atmospheres, which is quite destructive and could result in accidents more serious than for instant the recent Mont-Blanc tunnel accident. Unfortunately, major uncertainties remain on the mechanisms leading to detonation, even for hydrogen, the chemistry of which is better known than other more complex fuels, at least at relatively low pressures. In addition, there is reliable experimental evidence showing that a sudden release of high pressure hydrogen into the atmosphere may ignite spontaneously, under a mechanism that is not well understood either. The goal of the current work is to clarify the relationship between specific features of hydrogen chemistry and both appearance of a detonation and spontaneous jet ignition. To that effect, numerical simulation and mathematical analysis will be performed for a hierarchy of scenarios, starting from relatively simple ones to increasingly more complex and realistic ones.

氢是一种有吸引力的汽车燃料，因为它燃烧时不会释放二氧化碳或其他温室气体，也因为它是燃料电池的首选燃料。水力发电或风能产生的氢气是碳中性的。然而，由于与碳氢燃料相比，氢气具有明显不同的行为，在允许广泛的氢气储存和分配设施与人口稠密地区密切接触之前，需要解决重大的安全问题。同样，在隧道和公共车库的车辆中储存氢气也存在安全问题。由于氢气非常轻且具有浮力，通过确保不允许公众进入的地方周围有足够的距离，可以使户外安装变得安全。然而，在封闭的环境中，仍然存在严重的问题，主要与爆炸风险有关，氢比其他燃料更容易发生爆炸。爆震是最猛烈的燃烧形式，燃烧依靠冲击波进行，冲击波也受到它的支持。因此，只要遇到可燃混合物，爆轰波就会以高超音速传播，通常会导致数十个大气压的压力增加，这是非常具破坏性的，可能导致比最近的勃朗峰隧道事故更严重的事故。不幸的是，导致爆炸的机制仍然存在重大不确定性，即使是氢气也是如此，氢气的化学成分比其他更复杂的燃料更为人所知，至少在相对较低的压力下是这样。此外，有可靠的实验证据表明，高压氢突然释放到大气中可能会自发点燃，其机制也不是很清楚。目前工作的目标是澄清氢化学的具体特征与爆震和自燃喷流点火现象之间的关系。为此，将对一系列场景进行数值模拟和数学分析，从相对简单的场景到越来越复杂和现实的场景。