Towards a reliable and efficient furnace simulation tool for coal fired utility boilers

A validation exercise is presented with the objective of demonstrating that using a mature furnace simulation tool on high end supercomputers enables the reliable prediction of coal-fired utility boiler performance within short time frames. The tool used in the present investigation is the in-house developed 3D-furnace simulation code AIOLOS. To prove the predictive capabilities of AIOLOS the code is applied to the numerical simulation of three different industrial furnaces differing in the firing concepts, sizes and fuels. The discretizations range from 100,000 to 2,000,000 computed cells. Numerical predictions of AIOLOS are validated with measurements of temperature, wall heat fluxes, carbon in fly ash, and species concentrations provided by the industrial partners ENEL, Saarberg and RWE. The comparison of measured and calculated values showed that predictions with AIOLOS are accurate enough to enable the virtual optimization of combustion equipment in large scale utility furnaces. Furthermore, the vector and parallel performance of AIOLOS on the parallel vector computer NEC SX-4/32 has been assessed. The performance results showed that for the above mentioned calculations the runtime can be reduced to a couple of hours being short enough for industrial purposes.