Control of Hydrogen and Enriched-hydrogen Reacting flows with Water injection and Intensive Strain for ultra-low Emissions

Introduction

We are racing against time to find a clean, yet abundant, energy source able to arrest global warming. Hydrogen has all the characteristics to address this challenge: it can be produced cleanly from water; it is incredibly energetic; and more importantly, it is carbon-free.

Challenges of Hydrogen

However, hydrogen’s strong reactivity and diffusivity make the control of its flame in energy-generation devices extremely challenging. Moreover, toxic nitric oxides (NOx), a major concern for air quality, are still abundantly produced in a hydrogen flame. Enabling the use of hydrogen requires solutions where the flame is stable and has ultra-low NOx at the same time, and at any power setting.

Research Focus

In this research, I will study, for the first time, the combination of intensive strain and water injection in the context of lean premixed combustion. My preliminary research has indicated that:

1. Intensive strain improves the reactivity of the hydrogen flame.
2. It simultaneously pushes the NOx down significantly, a property yet to be understood.
3. Water injection further reduces the NOx but commonly causes flame extinctions and inefficiencies.

The combination of hydrogen and intensive strain, by enhancing the flame, offers a way of surpassing these limitations and further allows for operating the flame at richer conditions, thus preventing common instabilities from occurring in lean premixed combustion.

Research Objective

The objective of this research is to push the hydrogen flame into a high-strain regime characterised by a stable flame and ultra-low NOx. This research aims to find the extreme limits and physical knowledge allowing full control of the reacting flow in such a regime.

Methodology

The flame dynamics, still unknown in this regime, will be explored for the first time and fully characterised in this research by using:

• High-fidelity simulations
• Experiments
• Theoretical analyses

The gathered understanding will allow the control of hydrogen flames at any power setting. This will pave the way for the exploitation of green energy.