Dry lignite Cofiring in a Greek utility boiler: Experimental activities and numerical simulations

Agraniotis, M; Stamatis, D; Grammelis, P; Kakaras, E

dc.contributor.author	Agraniotis, M	en
dc.contributor.author	Stamatis, D	en
dc.contributor.author	Grammelis, P	en
dc.contributor.author	Kakaras, E	en
dc.date.accessioned	2014-03-01T01:33:11Z
dc.date.available	2014-03-01T01:33:11Z
dc.date.issued	2010	en
dc.identifier.issn	0887-0624	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20361
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Engineering, Chemical	en
dc.subject.other	Boiler operations	en
dc.subject.other	Co-firing	en
dc.subject.other	Co-utilization	en
dc.subject.other	Coal cofiring	en
dc.subject.other	Combustion behavior	en
dc.subject.other	Drying process	en
dc.subject.other	Efficiency increase	en
dc.subject.other	Experimental campaign	en
dc.subject.other	Increased temperature	en
dc.subject.other	Large scale boilers	en
dc.subject.other	Low temperatures	en
dc.subject.other	Numerical simulation	en
dc.subject.other	Operational behavior	en
dc.subject.other	Outlet temperature	en
dc.subject.other	Percentage points	en
dc.subject.other	Pre-drying	en
dc.subject.other	State of the art	en
dc.subject.other	Temperature field	en
dc.subject.other	Thermal utilization	en
dc.subject.other	Utility boiler	en
dc.subject.other	Wall heat flux	en
dc.subject.other	Boiler firing	en
dc.subject.other	Coal combustion	en
dc.subject.other	Computer simulation	en
dc.subject.other	Curing	en
dc.subject.other	Experimental reactors	en
dc.subject.other	Fuels	en
dc.subject.other	Pulverized fuel fired boilers	en
dc.subject.other	Steam power plants	en
dc.subject.other	Lignite	en
dc.title	Dry lignite Cofiring in a Greek utility boiler: Experimental activities and numerical simulations	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/ef1002843	en
heal.identifier.secondary	http://dx.doi.org/10.1021/ef1002843	en
heal.language	English	en
heal.publicationDate	2010	en
heal.abstract	Lignite predrying and dry lignite firing is considered as an important development step for the next generation of lignite power plants. The integration of a predrying system in future lignite power plants, which utilizes low temperature steam for the drying process, combined with the further thermal utilization of lignite's evaporated moisture, may bring an efficiency increase of four to six percentage points compared with today's state of the art. Firing predried lignite is however expected to cause certain changes in the combustion behavior of large scale boilers. The investigation of these changes in an existing Greek utility boiler through experimental activities and numerical simulations is the scope of the present work. The investigations take place in a 75 MWth lignite fired Greek boiler. The specific unit is equipped with dedicated dry lignite burners. The measurements are performed with a dry lignite thermal share of 6%. Higher cofiring thermal shares of up to 20% are further simulated and the effect of cofiring on the combustion behavior is evaluated by specific parameters including temperature fields, wall heat flux, fuel's burnout, and NOx emissions. No clear effects of cofiring on boiler operation are observed during the experimental campaign indicating that the operational behavior in low cofiring shares remains constant. Some trends are observed in the simulations of the dry coal cofiring cases. Increased temperature peaks in the near burner region and higher furnace outlet temperatures are predicted. A clear increase of the total fuel burnout when firing dry coal is also foreseen by the simulations, which is a strong argument for the coutilization of dry lignite as a supportive fuel. The overall examinations imply that dry lignite cofiring for low thermal shares up to 20% is feasible in the case of Greek boilers without major technological difficulties. For the realization of a lignite predrying concept in an existing Greek boiler however, a detailed study on each particular boiler is necessary. © 2010 American Chemical Society.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Energy and Fuels	en
dc.identifier.doi	10.1021/ef1002843	en
dc.identifier.isi	ISI:000283111200020	en
dc.identifier.volume	24	en
dc.identifier.issue	10	en
dc.identifier.spage	5464	en
dc.identifier.epage	5473	en