Numerical exploration and modelling of novel environmentally friendly combustion technique: droplet-laden MILD combustion

新型环保燃烧技术的数值探索和建模：液滴负载 MILD 燃烧

• 批准号: EP/S025154/1
• 负责人: Nilanjan Chakraborty
• 金额: $ 43.7万
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FS025154%2F1
• 关键词: Numerical; exploration; modelling; novel; environmentally

A small reduction in NOx emission per kilo-watt of generated power will have a significant reduction in environmental impact of combustion used for power generation. The MILD (Moderate or Intense Low-Oxygen Dilution) combustion technique offers an opportunity to drastically reduce emissions while improving thermal efficiency of furnaces and boil-ers. In gas turbines, though overall fuel-air mixture is fuel-lean and MILD combustion is not directly applicable, fuel-rich regions in the primary zone of the combustor exhibit localised MILD regimes, particularly for liquid fuel operation How-ever, the physical and chemical intricacies of this novel technique are not well understood and thus identifying key con-trol parameters for using this technique for power generation and industrial processes over wide range of conditions is challenging. This project aims to provide a step change in physical understanding and modelling of this combustion technique and to identify key control parameters. The aim is to investigate MILD combustion of high calorific value gaseous and liquid fuels for practical application using Direct Numerical Simulations (DNS) and Large Eddy Simula-tions (LES), with high-fidelity mathematical description for physical and chemical processes involved. The droplets of liquid fuel spray will be tracked using the Lagrangian approach while the gas phase is treated using the Eulerian ap-proach for the simulations. The effects of droplet diameter, equivalence ratio (both for gaseous and liquid fuels), extent of dilution by combustion products, volatility (by considering different fuels), turbulence intensity and its length scale on the burning rate, flame structure (in terms of chemical reaction pathways analysis and flame and flow topologies) and pollutants formation will be analysed based on a judicious parametric analysis based on three-dimensional detailed chemistry DNS data. In this project, the fundamental physical understanding extracted from DNS data will be utilised to develop high-fidelity models for engineering Computational Fluid Dynamics (CFD)-based simulations to identify key control parameters using LES after validating these models against the available experimental results. This project will provide (1) a ro-bust modelling framework for MILD combustion technique, which would be a cost-effective reliable tool for designing energy-efficient and clean gas turbines and industrial furnaces and (2) the key control parameters identified can help to design retro-fit "greener" combustion systems.

每公斤发电的NOx排放量略有减少将显着减少用于发电的燃烧的环境影响。轻度（中等或强烈的低氧稀释）燃烧技术为大幅度减少排放提供了机会，同时提高了炉子和沸腾剂的热效率。在燃气轮机中，尽管总体燃料空气混合物是燃料薄的，并且温和的燃烧不适用，燃烧器的主要区域中的富含燃料富含区域表现出局部的轻度制度，尤其是对于液体燃料操作，这种新技术的物理和化学复杂性，该新技术的物理和化学复杂性并不能很好地理解，因此可以识别出该技术的范围，用于使用该技术范围来进行挑战，并且可以使用该技术来实现范围。该项目旨在提供对这种燃烧技术的物理理解和建模的步骤，并确定关键控制参数。目的是研究使用直接数值模拟（DNS）和大型涡流模拟（LES）的高热量气态和液体燃料的轻度燃烧，并在涉及的物理和化学过程中进行高保真数学描述。液体燃料喷雾剂的液滴将使用拉格朗日方法跟踪，同时使用Eulerian Ap-track进行模拟处理气相。液滴直径，等效比（用于气体和液体燃料的等效比），燃烧产物稀释程度，波动性（通过考虑不同的燃料），湍流强度及其长度的规模对燃烧速率，燃烧速率（基于化学反应路径的分析和流动拓扑分析）的燃烧速率（在燃烧速率上）进行了分析，并分析了对污染物的详细参数，并分析了对详细的参数，并分析了对详细的参数，并分析了对污染的范围，并分析了对污染的介绍，并将DNS数据。在该项目中，将利用从DNS数据中提取的基本物理理解来开发用于工程计算流体动力学（CFD）基于模拟的高保真模型，以在对这些模型验证这些模型的可用实验结果后使用LES识别关键控制参数。该项目将提供（1）用于轻度燃烧技术的RO破坏建模框架，该框架将成为设计能效节能，清洁的燃气轮机和工业炉的经济高效的可靠工具，并且（2）所识别的关键控制参数可以帮助设计恢复拟合的“绿色”燃烧系统。

项目成果

Flame Self-interaction and Flow Topology in Turbulent Homogeneous Mixture n-Heptane MILD Combustion

正庚烷湍流均质混合物轻度燃烧中的火焰自相互作用和流动拓扑

• DOI: 10.1007/s10494-023-00401-w
• 发表时间: 2023
• 期刊: Flow, Turbulence and Combustion
• 作者: Abo-Amsha K

An Assessment of the Validity of Damköhler's Hypotheses for Different Choices of Reaction Progress Variable in Homogenous Mixture Moderate or Intense Low-Oxygen Dilution (MILD) Combustion

均质混合物中度或强低氧稀释 (MILD) 燃烧中 Damköhler 假设不同反应进程变量选择的有效性评估

• DOI: 10.1007/s10494-023-00520-4
• 发表时间: 2023
• 期刊: Flow, Turbulence and Combustion
• 作者: Awad H

Surface Density Function and Its Evolution in Homogeneous and Inhomogeneous Mixture n -Heptane MILD Combustion

均质和非均质混合物正庚烷轻度燃烧的表面密度函数及其演化

• DOI: 10.1080/00102202.2023.2182197
• 发表时间: 2023
• 期刊: Combustion Science and Technology
• 影响因子: 1.9
• 作者: Abo-Amsha K

A priori direct numerical simulation assessment of MILD combustion modelling in the context of large eddy simulation

大涡模拟背景下 MILD 燃烧模型的先验直接数值模拟评估

• DOI: 10.1016/j.fuel.2023.130295
• 发表时间: 2024
• 期刊: Fuel
• 影响因子: 7.4
• 作者: Awad H

Flame self-interactions in MILD combustion of homogeneous and inhomogeneous mixtures

均质和非均质混合物轻度燃烧中的火焰自相互作用

• 发表时间: 2023
• 作者: Awad, HSAM