| As one of the key parts of the coal water slurry gasification,the water system is used in water circulation in the process of gasification and to reduce the water consumption and waste water production of the plant.Whether or not the water system functions well is closely related to the stable and high-load operation of the gasification equipment,as well as the lifespan of the key equipment.Ash deposition and scale formation will bring about lots of harm to water system during coal water slurry gasification,including the space reduction of gasification reaction in gasifier;the decrease in gas circulation are of rough coal(for example:annular plug of downcomer and upcomer and scaling plug in rough coal gas exit of the gasifier);nasty cold water system and pipeline blocking;blocking and hole shrinkage of black and grey water pipeline;the failure of heat exchanger and the choke of local valve.All these issues will lead to some unexpected consequences as followings:Rough coal gas flow velocity increasing under the same loading will result in liquid drag-out;Local overheating of downcomer will give rise to the risk of equipment failure;The water volume decrease will lead to overheating of gasifier;The decrease of black water tonnage will result in worse water quality;The decrease of gray water supply will not satisfy the operation condition of gasifier;Frustration of rough coal gas flow;Power system wears and tears and so on.The entire above problems can made the Gasification unit load operation or shutdown,which influenced the steady for a long period of time of the equipment,hence investigated the reason of the problem and the main optimization measures is very important.In this paper,we studied the source of the scale of the components.Investigate the scale reason of Ca,Mg and metasilicate,all the factors incuded the Temperature,Pressurs,Medium flow rate,pH,Water system of solid content and so on,which influence the reasons of fouling has been analyzed.It has taken much time for investigated and blended the coal,which can made the coal much optimization,at the same time we has added the sewage treatment and combined the practice of industrial,from optimization of drugs,optimization of industrial operation,choose new technology and other aspects were analyzed.Expand scale control and deal with more measures,and attempt to improve and ease the gasification of the water system scaling problems. |
