Net Zero: Flame Instability of Ammonia Aerosol Combustion

净零：氨气溶胶燃烧的火焰不稳定性

• 批准号: ST/W002272/1
• 负责人: Sven Van Loo
• 金额: $ 17.86万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FW002272%2F1
• 关键词: Net; Zero; Flame; Instability; Ammonia

In the search for renewable and carbon-free fuels, the use of ammonia is considered an attractive solution for engine and gas turbine applications. When compared to other carbon-free fuels, such as hydrogen, it has significant advantages. Not only is it easy to produce from renewable sources of nitrogen and hydrogen, it is safer to store and transport and has a higher energy content. Furthermore, it can be produced, transported and distributed without changing the infrastructure already deployed by industries. However, for the successful application of ammonia as a fuel, one main challenge related to its combustion needs to be overcome: its low reactivity requires a high ignition energy, a narrow flammability range and low burning velocity. This complicates the stabilisation of the combustion flame and thus inevitably causes unreliable ignition and unstable combustion.The combustion of clouds of fuel droplets (or aerosol clouds) is of practical importance in gas turbines, diesel and spark ignition engines, furnaces and hazardous environments. There is experimental evidence that, contrary to expectations, flame propagation in aerosol clouds, under certain circumstances, is higher than that in a fully vaporised homogeneous mixture (possibly by up to a factor of 3). Also, the presence of fuel droplets is shown to enhance the generation of flame wrinkling instabilities. With richer mixtures and larger droplets, it is possible for droplets to enter the reaction zone and further enhance existing gaseous phase instabilities through the creation of yet further flame wrinkling. Therefore, the flame experiences periodic deceleration and acceleration with these oscillations lasting for several cycles within 100ms. Surely, the burning velocity enhancement may be advantageous in giving more rapid burning when burning ammonia in a gas turbine. As ammonia aerosol combustion has not been extensively studied yet, it is necessary to make clear to what extent ammonia aerosol flames inherit this oscillating behaviour as this oscillation of the flame will couple with thermo-acoustic oscillations and damage the turbine blades.While some theoretical research has studied flame propagation in aerosol clouds, the processes governing flame oscillations are still unclear, especially for ammonia. We will use the numerical techniques and hydrodynamics codes developed at the University of Leeds for STFC-funded astrophysical research to increase our comprehension of this phenomenon and advance ammonia as a carbon-free fuel.

在寻找可再生和无碳燃料的过程中，使用氨被认为是发动机和燃气轮机应用的有吸引力的解决方案。与其他无碳燃料（例如氢）相比，它具有显着的优势。不仅可以从可再生氮和氢的可再生能源产生，而且可以更安全地存放和运输并具有更高的能量含量。此外，它可以生产，运输和分发，而不会改变行业已经部署的基础设施。但是，要成功地将氨的应用作为燃料，需要克服与其燃烧相关的主要挑战：其低反应性需要高点火能量，狭窄的易燃性范围和低燃烧速度。这使燃烧火焰的稳定复杂化，因此不可避免地会引起不可靠的点火和不稳定的燃烧。燃油液滴云（或气溶胶云）的燃烧在燃气涡轮机，柴油机和火花点火引擎，炉子，炉子，炉子和危险环境中至关重要。有实验证据表明，与期望相反，在某些情况下，气溶胶云中的火焰传播高于完全蒸发的均匀混合物中的火焰（最高为3倍）。同样，燃油液滴的存在被证明可以增强火焰皱纹不稳定性的产生。借助较丰富的混合物和较大的液滴，液滴可以进入反应区，并通过产生进一步的火焰皱纹来进一步增强现有的气态相位不稳定性。因此，火焰经历了周期性的减速和加速度，这些振荡持续了100毫秒内的几个周期。当然，在燃气涡轮机中燃烧氨时，燃烧速度的增强可能是有利的。由于尚未对气雾氨气溶解燃烧进行广泛的研究，因此有必要在多大程度上表明气动火焰氨气燃料继承了这种振荡行为，因为这种振荡将与热声振荡息息相关，并损害涡轮的热量振荡，并损害涡轮的叶片。在某些理论研究中，一些理论上的范围是在范围内进行的，尤其是在空气中的流动范围，该进程是在空气中的流动，而不是涡轮增压。氨。我们将使用在利兹大学开发的数值技术和流体力学代码，用于STFC资助的天体物理研究，以提高我们对这一现象的理解，并将氨作为无碳燃料。