High Hydrogen Content (HHC) Fuel Burning at High Pressure

要想在2020年之前切实减少碳足迹，就必须在新的国际气候协定生效之前采取密集行动。燃烧是这一挑战的核心：化石燃料燃烧约占温室气体排放量的三分之二，因为全球80%以上的能源消耗是基于化石燃料。在世界范围内，化石燃料每年向大气中增加超过250亿吨的二氧化碳，沿着大量的其他污染物。这给提高运输和发电设备的燃烧效率和低排放带来了巨大的压力，同时开发更多样化的燃料流，包括低碳燃料。在迈向清洁燃烧技术的过程中，高氢含量（HHC）替代燃料混合物，特别是含有大量氢的那些混合物，无疑是重要的，因为它们是环境友好的，并且可以用作清洁能源生产中的能源的替代原料。不幸的是，由于三个主要原因，HHC燃料的技术适用性从根本上和实际上都表现出重大挑战。首先，HHC燃料的燃烧过程与高水平的扩散性和火焰温度相关联，这影响火焰速度、热释放速率、污染物形成，并且更重要的是影响火焰稳定性机制。其次，发电和运输中的内燃机通常在高压（例如10-100巴）下操作。目前的燃烧化学模型由数千个反应的动力学数据组成。这些模型进行了验证，通过详细的比较与广泛的火焰特性的实验观察。然而，大部分验证是针对低压（例如1巴）进行的，而燃烧装置大多在高得多的压力（例如20-100巴）下起作用。第三，关于在高压下燃烧的HHC燃料的排放物形成的信息较少/没有。由于在高氢燃料中发现的广泛的组成，非常适合于常规燃料如天然气的低排放性能的策略可能不一定对含氢燃料最有效。因此，许多现有的用于碳氢化合物含量燃料的燃烧器将需要新的和改进的技术来实现安全和可控的HHC燃料在高压下燃烧，这对于未来的清洁燃烧技术发展至关重要。因此，显然需要研究高压下替代清洁燃料的燃烧科学。为了应对HHC燃料在高压下燃烧所带来的挑战，非常需要通过系统地改变不同高压水平下燃料组合物的百分比来进行详细的参数研究。该提案的目的是开发新的计算实验，从根本上了解HHC燃料在高压条件下的燃烧问题。该项目将展示如何使用新的预测工程模型来利用HHC燃料，突出高压对清洁燃料燃烧，整体性能，排放分布的影响，并最终提供优化的工业指南，以设计高压下富氢清洁燃料燃烧的燃烧室性能。工业指南将特别说明富氢清洁燃料燃烧对燃气涡轮机燃烧的适用性和可操作性。该项目将研究高压对HHC燃料燃烧的影响，并生成一个全面的计算数据库，以便为高压下富氢燃料的燃烧问题制定工业指南。

To have a realistic chance of reducing the carbon footprint before 2020, intensive actions are required before the date by which a new international climate agreement is due to come into force. Combustion is at the heart of this challenge: fossil fuel combustion accounts for around two-thirds of greenhouse-gas emissions, as more than 80% of global energy consumption is based on fossil fuels. Worldwide, fossil fuels add more than twenty five billion tons of carbon dioxide to the atmosphere every year, along with vast quantities of other pollutants. This places enormous pressure to improve the combustion efficiency with low emissions in transportation and power generation devices while simultaneously developing more diverse fuel streams, including low carbon fuels. In moving towards cleaner combustion technologies, high hydrogen content (HHC) alternative fuel blends, especially those containing significant quantities of hydrogen are undoubtedly significant, because they are environmentally friendly and can be used as an alternative feedstock for energy resources in the clean energy generation. Unfortunately, the technical applicability of HHC fuels exhibit major challenges both fundamentally and practically due to three major reasons. Firstly, the combustion processes of HHC fuels is associated with high level of diffusivity and flame temperature which affect the flame speed, heat release rate, pollutant formations, and more importantly flame stability mechanisms. Secondly, combustion engines in power generation and transportation are generally operating at high pressure (e.g. 10-100 bar). Current chemical models for combustion consist of kinetic data of thousands of reactions. These models are validated through detailed comparisons with wide ranges of experimental observations of flame properties. However, much of the validation has been done for low pressure (e.g. 1bar), whereas combustion devices are mostly functioning at much higher pressure (e.g. 20-100 bar). Thirdly, there is less/no information available regarding the emission formations of HHC fuel burning at high pressure. As a result of the wide range of compositions found in high hydrogen fuels, strategies well suited for low emissions performance on conventional fuels such as natural gas may not necessarily work best for hydrogen containing fuels. Because of this, many existing combustors used for hydrocarbon content fuels will require new and refined techniques to achieve safe and controllable HHC fuel burning at high pressure, which is crucial for future clean combustion technology developments. Therefore, there is a clear need to investigate the combustion science of alternative clean fuels at high pressure. In order to meet the challenges posed by the HHC fuel burning at high pressure, a detailed parametric study by systematically varying the percentage of the fuel composition at different high pressure levels is highly desired. The aim of this proposal is to develop new computational experiments to fundamentally understand the burning issues of HHC fuels at high pressure conditions. The project will demonstrate how the new predictive engineering models can be used to utilise HHC fuels, highlighting the effects of high pressure on clean fuel burning, overall performance, emission distributions and finally provide an optimised industrial guidelines to design combustor performance for hydrogen-rich clean fuel burning at high pressure. The industrial guidelines will particularly address the applicability of hydrogen-rich clean fuel burning for gas turbine combustion and operability. This project will investigate the effects of high pressure on HHC fuel burning, and to generate a comprehensive computational database in order to establish industrial guidelines for burning issues of hydrogen-rich fuel at high pressures.