Research On The Influence Of Zhundong Coal Blended With Kaolin On Boiler Operational Performance

Zhundong Coal Field is known because of its abundant coal reserves,but Zhundong coal has a natural inherent problem,its high alkali metal content,which makes it easy to cause contamination,slagging,and corrosion during boiler combustion.Most of the newly commissioned boilers in Xinjiang have been designed to prevent slagging or use other measures to alleviate slagging.However,for some boilers that have been put into use for a long time and are not designed to be easily slagging coal,they often face the problem of boiler slagging when using Zhundong coal as fuel.They can only seek to mix and burn coal with low content of alkali metals(Na,K,etc.)or other additives to prevent slagging,which severely restricts the utilization of Zhundong coal and the economic development of enterprises.Because of its unique geographical advantages,the Zhundong area not only has abundant coal reserve,but also a large amount of kaolin around it.Studies have shown that kaolin is a good anti-slagging additive,so adding kaolin to Zhundong coal for blending has good practical significance and social application prospects.The boiler of a 350 MW unit in a power plant has serious slagging and contamination problems when burning high-sodium coal,and it needs to be mixed with high-priced lowsodium coal.This paper uses kaolin to find a way to alleviate the boiler's slagging.First,analyze the mechanism of coal-burnt boiler slagging,contamination and corrosion and the factors that affect them.Therefore,draw the conclusion that kaolin as an additive can reduce slagging,contamination and corrosion.Then,combined with the basic situation of the power plant's boiler equipment,the main problems currently existing were clarified,the main research content was determined,and the research plan was formulated.Next,a laboratory study on the blending of kaolin with Zhundong coal was conducted,from the aspects of coal ash sintering ratio,fuel wear characteristics,one-dimensional furnace blending,and coal ash abrasion,etc.,and an 8% best blending ratio of kaolin was obtained,as well as carrying on the numerical simulation of the corrersponding working condition.Finally,the reformed boiler was carried out on the actual furnace test of Zhundong coal blended with kaolin.The research results showed that the reformed and adjusted boiler has good adaptability to allburning Zhundong coal,and the degree of boiler slagging,contamination and corrosion is obviously lighter.Considering indicators such as slagging,contamination,heat transfer,metal wall temperature,load capacity,etc.,the safety of the boiler for fully burning Zhundong coal has been greatly improved.Economic indicators such as boiler efficiency and environmental protection costs have also improved to a certain extent.The performance of the boiler is fully adapted to Zhundong coal blended with kaolin.In this paper,through the research on the blending of all-burning Zhundong coal with kaolin in boilers,some experience and conclusions about the transformation of all-burning Zhundong coal have been obtained,which will provide certain reference for similar boiler transformation.