High Hydrogen Content (HHC) Fuel Burning at High Pressure

为了在2020年前有一个减少碳足迹的现实机会，在新的国际气候协议即将生效之前，必须采取密集的行动。燃烧是这一挑战的核心：化石燃料燃烧约占温室气体排放的三分之二，因为全球80%以上的能源消耗基于化石燃料。在世界范围内，化石燃料每年向大气中增加超过250亿吨二氧化碳，以及大量其他污染物。这给交通运输和发电设备带来了巨大的压力，需要在低排放的情况下提高燃烧效率，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，高含氢量(HHC)替代燃料混合燃料，特别是那些含有大量氢气的混合燃料无疑具有重要意义，因为它们对环境友好，可以作为清洁能源发电中的能源替代原料。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践上都面临着重大挑战。首先，HHC燃料的燃烧过程与高扩散率和火焰温度有关，这会影响火焰的速度、放热率、污染物的形成，更重要的是影响火焰的稳定机制。其次，发电和运输中的内燃机通常在高压(例如10-100bar)下运行。目前的燃烧化学模型由数千个反应的动力学数据组成。这些模型通过与广泛的火焰特性实验观测进行详细的比较而得到验证。然而，大部分验证都是针对低压(例如1bar)进行的，而燃烧装置大多在更高的压力(例如20-100bar)下运行。第三，关于高压燃烧的HHC燃料的排放形式，现有的资料较少，甚至没有。由于高氢燃料的组成范围很广，适合天然气等常规燃料低排放性能的策略不一定对含氢燃料最有效。因此，许多现有的用于碳氢燃料的燃烧器需要新的和改进的技术来实现HHC燃料在高压下安全和可控的燃烧，这对未来清洁燃烧技术的发展至关重要。因此，显然有必要对替代清洁燃料的高压燃烧科学进行研究。为了应对HHC燃料在高压下燃烧带来的挑战，迫切需要通过系统地改变不同高压水平下燃料组成的百分比来进行详细的参数研究。这项提议的目的是开发新的计算实验，以从根本上了解HHC燃料在高压条件下的燃烧问题。该项目将演示如何使用新的预测工程模型来利用HHC燃料，重点介绍高压对清洁燃料燃烧、整体性能和排放分布的影响，并最终提供优化的行业指南，以设计高压燃烧富氢清洁燃料的燃烧室性能。工业指南将特别涉及富氢清洁燃料燃烧对燃气轮机燃烧的适用性和可操作性。该项目将调查高压对HHC燃料燃烧的影响，并生成一个全面的计算数据库，以便为在高压下燃烧富氢燃料问题制定行业准则。

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.