Last week, I spent two very worthwhile days in Stockholm, Sweden, participating in the latest in the biennial series of ‘Nordic Flame Days’ organised jointly by the Swedish and Finnish Flame Committees (SFRC and FFRC) of IFRF and the Scandinavian-Nordic Section of the Combustion Institute (CINS).  Building on the success of the 2013 and 2015 Flame Days in Jyväskylä (Finland) and Copenhagen (Denmark) respectively, the 2017 meeting was hosted by KTH, the Royal Institute of Technology, at their magnificent campus in northern Stockholm.

There was a lively ‘buzz’ amongst the 96 registered participants as Fredrik Normann of Chalmers University of Technology and chair of SFRC got the proceedings going, introducing two very informative ‘keynote’ talks. 

Firstly, Mikael Odenberger – also from Chalmers – described the important role of combustion in the likely energy systems of the future:  While renewable energy sources (notably wind and solar) will play an increasingly important role in electricity generation, the need to decarbonise heat and transportation sectors will mean that thermal combustion plants will complement variable renewables, and in some cases, continue to serve as the backbone technology.  The ‘coupling’ of sectors such as electricity, heat, fuels, chemicals, etc. will present unique opportunities for combustion-based processes, particularly in addressing the increasing flexibility requirements of, and starts/stops in, energy infrastructures incorporating higher penetrations of renewables.

Jeanette Obling of DONG Energy A/S (which, following its divestment of all its upstream oil and gas assets and a clear future focus on renewables, is likely to be renamed ‘Ørsted A/S’ – a reference to innovative Danish scientist Hans Christian Ørsted whose discovery of electromagnetism in 1820 helped lay the scientific foundation for modern power generation technologies) outlined how the company was part way through an extensive conversion of its fossil-fuel-fired combined heat and power plants to biomass-firing.  To date, plant with a total power capacity of 1262MW_e (producing 2158MWh of energy) has been converted – part of a programme that will see the company move from 7% of its power generation sourced from biomass in 2006 to 82% in 2023 (with no coal consumed in its CHP plants).  Jeanette gave her perspective on the key challenges to be addressed in this transformation, the main one being fire and explosion safety in biomass transport, storage and handling.

After a networking lunch, two or three parallel technical sessions took place, covering diagnostics/in-flame measurements, fuel flexibility, reaction modelling & optimisation, ash formation & management, heterogeneous sub-models, corrosion and combustion concepts – with many excellent presentations from both industrial and academic researchers.  These, along with a plenary address on the past, present and future of IFRF by me, and an excellent reception and dinner in the 155m high Kaknästornet TV tower looking across the city centre to the west and the archipelago to the east, completed Nordic Flame Day #1.

With all ‘ice broken’ (metaphorically, not literally), much networking was evident on Flame Day #2, including a networking coffee break for the Scandinavian-Nordic section of the ‘Women in Combustion’ network – more on that in the next edition of MNM.  Again, two keynote speakers set the scene for the day’s technical content.

Andrea Gruber of SINTEF in Norway amazed the participants with the sheer scale of the large-scale numerical simulations that underscore the present and future modelling of turbulence and combustion in thermal systems.  Some of the simulation runs that Andrea showed us can take a day or more to run on some of the world’s most powerful supercomputers – such the US DOE/NOAA ‘Titan’ Cray >17petaFLOPS hybrid supercomputer at ORNL, which has a power rating of 8.2MW_e and can use 70-80MWh of energy for some of the simulations!  The way such modelling and simulation is heading, increased use of parallel processing using multiple HPCs (e.g. using the ‘Legion’ framework) will be needed.

Talking of large-scales of operation, Johan Hult of MAN Diesel & Turbo SE presented how lab- to large-scale optical/laser diagnostic techniques have been used by MAN to optimise the design and operation of its enormous two-stroke marine propulsion engines – these direct-drive engines, used to propel supertankers/carriers, have cylinder bores of up to 1m and stroke lengths of up to 3m…  As Johan pointed out, the power output of his larger engines nicely matches the power consumption of some of Andrea’s turbulence simulations!  MAN have used high-speed imaging, IR thermography, Mie scattering, PIV and thermographic phosphor optical techniques to optimise the efficiency, reliability and environmental performance of its engines. 

Andrea’s talk served to underscore a CINS Topical Session on large-scale numerical simulations, while Johan’s talk linked very nicely with other technical sessions on modelling, combustion chemistry, diagnostics/in-flame measurements and emission control – again, with many excellent technical presentations delivered from industry and academia.

As a new IFRF initiative, a more-or-less constant feed of Tweets were posted on Twitter, with the hashtag #NFD2017:  These have since been collated into a ‘Storify’ for Nordic Flame Days 2017 which you can view here.

All in all a great combustion event – well done to SFRC, FFRC and CINS…  I’m looking forward to the 2019 Nordic Flame Days already!