Ultra Low NOx Gas Turbine Combustion

What will I learn?
Gas turbines are a major source of new electricity generating plans, but they have to meet severe NOx and CO emissions legislation in many countries. This course will address the technology options for industrial gas turbines necessary to meet 25ppm NOx regulations on liquid fuels and for <10ppm on natural gas (with 10ppm CO). The design options for low NOx combustors for liquid fuels for aero engine applications will also be discussed. The demand for <5ppm NOx in some countries has led to the course reviewing design features for low single digit NOx combustion. Combustion operating conditions for 1–3ppm NOx are overviewed as well as industrial gas turbine combustor redesign for 3ppm NOx compliance.

For aero-gas turbines, NOx reduction is becoming more important and future designs are following the design procedures of lean low NOx combustion from the industrial sector. However, the inlet temperature to the combustor is about 1000K with pressures of 60 bar at take-off and this creates severe problems for NOx control. As only liquid fuels are viable for aero-gas turbines the problem of fuel atomisation and auto ignition in premix ducts will be discussed.

The principles of low NOx designs are the same for all the applications of gas turbines and this course draws on information from the various gas turbine fields of aero, industrial and automotive as the cross fertilisation of ideas between the various areas is an important part of low NOx technology development. Each application area has its own specific problems which will be discussed on the course.

A common problem with low NOx gas turbines is that of acoustic resonance. Solutions to this problem are overviewed based on industrial combustor modifications that have been found to cure the problem.

How will I benefit?
This annual short course, now in its eighteenth year, is updated for each delivery with the latest publications on low NOx gas turbines. By undertaking this course, you’ll gain an understanding of:

  • fundamentals of NOx formation
  • CO emissions, film cooling, flammability, flame propagation, weak extinction and flashback
  • premixed low NOx combustors and the importance of fuel/air mixing
  • practical lean ultra low NOx combustors.

Day 1: Fundamentals of NOx formation

  • Gas turbine cycles for low carbon and carbon sequestration, implications for NOx
  • Thermal NOx formation kinetics
  • The pressure dependence of NOx – experimental evidence reviewed
  • Thermal NOx control techniques
  • Flue gas recirculation in low NOx gas turbines for enhanced exhaust gas CO2 to enable viable CCS to be applied
  • Prompt NOx, including N2O kinetics
  • Nitrogen dioxide emissions and formation
  • Fuel nitrogen NOx – the importance of low level fuel nitrogen in NOx emissions from liquid fuels such as gas oil.

Day 2: CO emissions, film cooling, flammability, flame propagation, weak extinction and flashback

  • CO and hydrocarbon formation and destruction
  • The influence of film cooling on CO, UHC and NOx emissions and the requirement of no primary zone film cooling for minimum NOx and CO emissions
  • Fundamentals of laminar and turbulent pre-mixed combustion and flammability limits
  • Weak extinction and lean flammability limits in premixed/prevaporised combustion
  • Flame stability requirements of gas turbine combustors and their incompatibility with single stage low NOx combustors. Fuel staging or air staging?
  • Turbulent flame propagation in premixed fuel/air mixtures
  • Premix/prevaporisation duct design and NOx emissions
  • Air staging low NOx combustors.

Day 3: Premixed low NOx combustors and the importance of fuel/air mixing

  • Lean low NOx acoustic instabilities and pressure oscillations
  • Low NOx technology premixed and staged combustors
  • The importance of flame stabiliser pressure loss on fuel/air mixing and NOx: experimental evidence
  • Air assist atomisation of liquid fuels
  • Liquid fuels (including alternative fuels) for gas turbines and their impact on combustion, emissions and deposits formation
  • Non-swirling baffle type combustors

Day 4: Practical lean ultra low NOx combustors

  • Axial swirl lean combustion
  • Radial swirl lean combustion
  • Counter-rotation axial swirlers
  • Counter-rotating radial swirlers
  • The development process applied to Siemens industrial turbomachinery’s dry low emission combustion technology
  • Development of the hybrid burner for the Siemens gas turbines
  • Fuel staging low NOx combustors.

Day 5: Practical ultra low NOx combustors

  • Combustor development for aeroderivative industrial gas turbines
  • Low NOx combustor development for aero-engines
  • Gas turbine combustion evolution
  • Gas turbines for syngas & hydrogen combustion
  • Low NOx technology
  • Lean/lean fuel staging without air staging and rich/lean low NOx combustors
  • Catalytic combustion for low NOx gas turbines.


This course is suitable for you if you have an interest in low NOx gas combustion. It will be of particular interest if you’re:

  • a combustion designer in gas turbine manufacturing
  • an operator of modern, low NOx electrical generation systems, including combined cycles
  • an automotive emissions engineer
  • an environmental legislator or regulator.

"Interesting and useful course for a combustion engineer. Wide range of topics regarding Ultra-Low NOx is discussed. The whole course is completely up to date with all recently published developments." OPRA Turbines

"Course was excellent and very useful for me.  I learned a lot about low NOx combustors, I hope it will help me in designing such device."   OJSC Aviadvigatel

"The Leeds Ultra Low NOx combustion course combines the theory, research and practical applications related to Gas Turbine Low NOx combustion in a perfect way.  It gives me a big benefit for my daily work." ALSTOM

This course is in association with the Institution of Diesel and Gas Turbine Engineers, which is devoted to the advancement of diesel and gas engines, gas turbines, and related products and technology. The course has also been approved by the Institution of Gas Engineers and Managers for continuing professional development (CPD) purposes.

The Energy Institute has approved Leeds University – Faculty of Engineering – as an Approved Training Provider.

The course is also supported by ASME International Gas Turbine Institute. The June 2017 Turbo Expo takes place in Charlotte, NC, USA on June 26-30, 2017. To find out more visit https://www.asme.org/events/turbo-expo.  

Full five days: £TBC

Any one day: £TBC

Fees include:

  • cost of tuition
  • course materials
  • lunches
  • light refreshments
  • course dinner
Jenny Carter + 44 (0)113 343 8104

CPD Conference and Events Unit
Faculty of Engineering,
University of Leeds,