Regulation Testing Research Of Combustion On 500MW Boiler

There are two 500MW supercritical pressure boilers in Pan Shan power station, which are designed to use bituminous in North Shan Xi, but really used coal is Shen Hua coal. The serious slagging is appeared after Shen Hua coal is used, which causes the TBF in bottom of boiler, problem in dust removal system, and flameout leading to outage.Analysis of ash slagging performance shows that Shen Hua coal used in the boiler has the serious slagging and fouling characteristic.Through the testing of cold air model of single burner and hot combustion regulation the conclusion is as below:(1)The position of secondary air baffle has obvious influence on outside flow field of burner;(2) When position of secondary air baffle is at 0~+15 the backing flow area and diffusing angle of outside flow field is good;(1) As the swirling intensity of the burner is strong the position of secondary air swirling baffle is not fit in 0;(2) If the coal is easy to be ignited the swirling intensity of secondary air can be weak, the position of secondary air swirling baffle is better in +10~+15, and the burner's operating situation will be checked and correctly regulated;(3) In order to get a good atmosphere and lower temperature near the waterwall and outlet of furnace, which is favorable to slagging controlling in boiler, the low oxygen operation model is not good. When the load is at 300-500MW the gas flow oxygen rate in furnace outlet, will be controlled in 5.5%, not below 5%;(4) When the load is below 60%MCR the better operation model is four pulverizers in operating; when the load is at 60%~80%MCR the better operation model is five pulverizers in operating; when the load is above 80%MCR the better operation model is six pulverizers in operating, the pressure of primary air should be controlled in 10kPa, air flow of pulverizer is at 75~90km3/h;(5) The effect of combution regulation .is limited other measures must be used.If the boiler is operated in correct way the stable and economic operation can be achieved at 500MW load and 100% Shen Hua coal.