Exploration of novel fuels for gas turbine applications

由于非石油燃料正在成为燃气涡轮机运营商的必需品，第二代生物燃料正在开发中，需要在未来几年内对其广泛使用进行评估。燃气涡轮机燃烧室中的燃烧是非常复杂的，其中许多强耦合变量相互作用以在具有非常严格的排放标准的有限空间中制备燃料空气混合物。因此，设计燃烧器的现有设计工具对于使用中的燃料的性质是非常特定的。分析相关性与模拟相结合是设计工具，用于解释以下现象：燃料蒸发、混合和扩散、强湍流气动流、高温对流和辐射流以及高能输送的强化学反应。因此，燃料特性是一个关键因素，以说明在高温下输送到涡轮机部分的流动的附加能量，但具有明确的轮廓以防止叶片侵蚀。设计中最重要的挑战是预测与反应滕佩密切相关的极低排放。因此，当在燃气涡轮机燃烧器中使用新燃料时，必须增强所有设计工具以考虑现有或新开发的燃气涡轮机燃烧器中的变化特性。生物燃料燃气涡轮机发动机的性能和污染物排放可以更准确地预测，使用验证的燃烧模型。本研究项目的目的是研究新型燃气涡轮机燃料在非燃烧和燃烧系统中的特性，以使它们与更简单的几何结构的相互作用解耦，从而识别控制燃烧现象的潜在变量，并从实验或数值数据中开发有用的相关模型。对于非燃烧系统，将用先进的激光技术表征燃料喷雾，以研究燃料性质的变化对液滴形成的影响以及送入燃烧室的最终尺寸分布。对于燃烧系统，它们将从简单的层流和湍流开放式燃烧器变化到复杂的旋流通用燃烧器，接近实际的工业燃烧器。该项目还将向生物燃料生产商提供反馈，以使其产品适合最终用户。

Since non-petroleum fuels are becoming a necessity for gas turbine operators, 2nd generation biofuels are in development and need to be evaluated for wide spread use in the coming years. Combustion in gas turbine combustors is very complex with many strongly coupled variables interacting to prepare the fuel air mixture in limited space with very stringent emission standards. Hence existing design tools to devise a combustor are very specific to properties of fuels in use. Analytical correlations paired with simulations are the design tools used to account for phenomena such as fuel evaporation, mixing and diffusion, the strong turbulent aerodyna- mic flow, the high temperature convective and radiating flow, and the strong chemical reaction with high- energy delivery. Therefore, fuel properties are a critical factor to account for added energy to the flow delivered to the turbine section at high temperature but with a well-defined profile to prevent blade erosion. The most significant challenge in design is to predict for very low emissions that are strongly coupled to reacting tempe- rature. Therefore when a new fuel is used in a gas turbine combustor, all the design tools have to be enhanced to account for changing properties in existing or newly developed gas turbine combustor. The performance and pollutant emissions for biofuelled gas turbine engines can be predicted with better accuracy, using validated combustion models. The objective of this research project is to study the characteristics of novel gas turbine fuels in non-combusting and combusting systems to decouple their interaction with simpler geometries to identify the underlying variables controlling the combustion phenomena and to develop useful correlation models from the experimental or numerical data. For non-combusting systems, fuel sprays will be characteri- zed with advanced laser techniques to study the influence of changing fuel properties on droplet formation and the ultimate size distribution fed to the combustor. For the combustion systems, they will vary from simple laminar and turbulent open burners, to complex swirl generic combustors, approaching realistic industrial combustors. This project will also provide feedback to biofuel producers to tailor their products to end users.