INJECTION TECHNOLOGY OF ENRICHED HYDROGEN GAS TO REDUCE SULFUR OXIDE AND FLY ASH EMISSION

摘要

This paper presents a CFD model and the first validation set of results concerning a new technology to inject and adsorb, under safe conditions, a hydrogen enriched gas in solid fuel that has been milled, at the burner inlets of a power designated steam boiler. The present paper presents a dynamic model of enrichment technology which refers to the improvement of the classical existent technological flow of the pulverized coal burning installation in order to prepare and burn weak volatile matters pulverized fuel. The model refers to obtain an enriched hydrogen pit coal by the injection of an hydrogen enriched gas into the average ground pulverized pit coal current, the control of the gas diffusion into the porous environment of the powder particles, process that is accelerated in comparison with other gaseous component parts due to the hydrogen atom / molecule characteristics, and finally, the adsorption of this molecule into coal particles. The complex nature of this model consists in: to issue and simulate the procedure to inject and diffuse the hydrogen enriched gas in the pulverized coal current; to design and to simulate an installation to enrich by injection the pulverized pit coal in primary mixture stream - a special attention is paid to the influence of the pit coal particles porosity upon the hydrogen adsorbing process; to develop a model to simulate the burners operation in these new conditions. Burning process of this enriched pulverized pit coal is expected to produce a strong decrease in sulfur dioxide emissions and also in the flying ash concentration at the end of the furnace. A set of preliminary experimental results concerning all aspects of this technology will be also presented. These results have been obtained on a laboratory scaled installation which is located at labs of the Politehnica University of Bucharest. This installation has a storage capacity of hydrogen, a 5000 rpm ventilator mill to prepare the solid fuel. Test equipment includes lloriba gas analyzer, high speed camera and all other facilities to determine all the operational parameters. Different types of burners can be installed at this installation in order to determine an optimal procedure.