Analysis of Nox formation enhances boiler efficiency
Part of a supercritical boiler's maximised functioning depends on the nature of its emissions, on such variables as flue gas properties, airflows, furnace configurations and steam cycles. Enhancing these features will not only improve state-of-the-art technologies, but also advance the European boiler industry as a whole. In order to understand internal combustion conditions, a methodology to analyse the formation of NOx in pulverised coal fired burners was developed. Based on previous experiences, the methodology consists of a basic furnace configuration. It is flexible in that it can incorporate several variables such as the position, shape and orientation of flow ports and used computational fluid dynamics to calculate flow, gas, particle mixing, heat transfer and NOx formation. Another development was the post-processing techniques in order to ascertain the carbon-in-ash and the gas mixing parameters from individual burners. Additionally, sets of tools were also established to perform energy and mass balances of arbitrary volumes. These tools along with appropriate judgement allow for the most suitable configurations for carbon-in-ash, NOx, formation and radiation heat transfer distribution. The methodology along with the tools should contribute towards the enhancement of the European boiler industry, being appropriate either for new boiler designs or to retrofit existing boiler models. The developers are available for consultancy and seek enterprise from power plant owners or boiler manufacturers.
