Title of Programme

TECHNICAL COAL RESEARCH PROGRAMME

TARGET AREA B4.A PREDICTION OF ASH SLAGGING AND FOULING

Financing Code for Project

7220-ED753

EUROPEAN COMMISSION RESEARCH

DIRECTORATE-GENERAL XVII, ENERGY

 

 

CIRCE

 

The effects associated to the mineral matter contained in the coal are the main single-factor affecting the efficiency and availability of coal-fired boilers. Their consequences include the fouling of convective surfaces, formation of slag deposits and high-temperature fireside corrosion, all of which result in efficiency losses, high maintenance costs and reduced availability of the unit.

Prediction and control of fouling rates and resulting deposit properties are essential for optimal power plant maintenance planning, improved energy efficiency and the development of rational methods to assess the fouling tedency of different fuels. Traditional approaches have been mainly based on the use of empirical indices for the assessment of the severity of fouling/slagging problems. These simplified methods can be effective in certain cases, but their lack of generality prevent their use with any type of coal (or mixtures of different coals) or in any combustion configuration.

The present project is aimed at the development and utilisation of testing and modeling tools for the analysis and prediction of the behaviour of the mineral matter in coal combustion. The proposed research addresses the imperative need for experimentally validated, engineering optimisation tools, able to predict the transformations of the inorganic material along the combustion chamber, and the dynamics of net deposit properties for surfaces exposed to the high temperature products of ash-bearning coal combustion.

• Development of tasting procedures and facilities for the characterisation of the evolution of the mineral matter in pulverised-coal combustion. This facility will allow a systematic and detailed characterisation of the fly-ash and ash-deposits obtained with a variety of coals and different combustion conditions, representative of those found in large pulverised-coal boilers.
• Generation of technological database enabling the comperative characterisation of the slagging and fouling behaviour of different coals.

Development of predictive models converning the different stages in the evolution of the mineral matter during the combustion of coals particles. Those models will address the formation of fly-ash  particles from the mineral inclusions initially contained in the coal, and the subsequent process of deposition on surfaces